February 17, 2023——A Citizen Science Project
In the last "With Clear Skies" column I wrote about the shocking loss of our night skies that has been happening since the introduction and wide spread adoption of LED outdoor lighting. Part of that article described the very low tech citizen scientist driven project used by researchers to determine the percentage of loss of our night sky on a year to year basis. If you missed that column you can find it (and a work in progress archive of all the others) at mt43news.com/00D.
The project they used is Globe at Night (mt43news.com/00C). It is simple and elegant in its premise. Step out into the night sky on a night when the Moon is not visible, look at a well known constellation like Orion and match what is seen with images provided on their web site. Note a few things like amount of cloud cover, location, setting, and additional comments. Click Submit and you're done.
If you happen to be using a smart phone to access the web page your location and time will be taken from the phone's GPS. The maps to match will be right there at arm's length.
Globe at Night is a part of the SciStarter project (mt43news.com/00E). SciStarter is a massive clearinghouse of literally thousands of citizen science projects. Not so much into astronomy but wild about trees? There are a ton of projects related to trees, or weather, or well, pick something.
Globe at Night has monthly campaigns and as I write this we are just in the beginning of the February campaign. The constellations to view are Orion or Gemini. Both are easy to find. The Globe at Night website has a handy real-time map to make it easy to find both.I've just signed up at SciStarter and will be logging my observations at Globe at Night with them. I'm also going to be browsing through the other SciStarter projects to find a few more that appeal to me.
I can't wait to get out under our dark Montana skies and match what my 66 year old eyes can see to the maps on the Globe at Night web site. I hope you'll join me.
When we next have clear skies, of course.
February 3, 2023—— Our Vanishing Night Skies
The January 20, 2023 issue of Science, a weekly publication from the American Association for the Advancement of Science, shocked the world with an article stating that light pollution across the globe has increased by 10% per year from 2011 on.
A summary article is here: https://mt43news.com/00A
The primary article is here: https://mt43news.com/00B
Briefly, the study analyzed data from the GlobeAtNight project (https://mt43news.com/00C), a Citizen Science project where folks like you and me went out on certain nights every month and reported through a web app what stars they could see in a specific constellation like Orion. The study reviewed over 51,000 of these citizen reports primarily from North America and Europe and cross referenced them against satellite generated maps from the same time.
The results showed how much "skyglow" has increased over the years. To see skyglow in Broadwater County, just step outside at night and look northwest toward Helena. The light dome you'll see has gotten much worse since I moved here in 2013. Under dark skies you'd also be able see skyglow from Bozeman to the southeast, Butte to the southwest, and Great Falls to the northeast.
This increase far exceeds what satellite data suggests because the vast increase in night illumination in the last decade has been from LEDs and their intense blue shifted light. The satellites used to track light pollution do not see this blue. Additionally, they are not very good a capturing horizontally projected light like you'd see on a massive LED billboard or lighting a building facade.
Communities around the world have begun implementing laws to alleviate light pollution and devices like horizontal cutoff hoods for outdoor lights can at least prevent light from beaming straight up to the benefit of no one. This study shows how ineffective these measures have been.
Life on Earth evolved with sunlight during the day and moonlight and starlight at night. Artificially lighting up the night has proven disastrous effects on everything from night migrating birds to our own sleep patterns.
We still have access to pristine night skies in most rural parts of Montana and areas with no visible lights at all are just a short drive away. Between the increase in artificial light and the proposed mega-constellations of low earth orbit satellites we are in real danger of losing forever the wonder and grandeur of the Milky Way sprawled across the night sky that we can all enjoy just by stepping out into the night.
With clear, and dark, skies, of course.
October 15, 2015
On Thursday, October 15, look for the three day old waxing crescent moon and Saturn together in the southwest in early evening. Saturn is the only planet still visible in the evening sky. We should be able to see Saturn continue to drop closer and closer to the Elkhorns in the early evening through the end of October. After that it will be too close to the sun to see until it reappears in the morning sky in December.
The morning sky is stunning now. If you step out around 7am under clear skies and look east, you will be able to see all of the rest of the planets that are visible to the unaided eye. Closest to the horizon is Mercury. On Friday October 16 it will reach its maximum western elongation from the Sun so this is as high in the morning sky as it will get.
Next in line and second brightest of the four planets is Jupiter. On Saturday October 17 it will be within a full moon's width of Mars. If you have a small telescope you will be able to easily see Jupiter, all four Galilean moons and Mars in the field of view. After the 17th Jupiter will be slightly above Mars but still close enough to make it easy to spot the red planet. Mars is not as bright as the other planets right now but by next May it will be as bright in the sky as Jupiter is now!
Finally, at the top of the line is Venus, the second brightest object in the night sky. Venus is on its way to its own maximum western elongation on October 26. If you look at Venus with a small telescope now you will see a half illuminated disc--looking very much like our own Moon when it is at First or Last Quarters.
Take a moment to step out into the early morning and savor the sight of four planets, hanging bright and beautiful in the eastern sky!
With clear skies, of course.
October 1, 2015
Last Sunday we had a great turnout for our public viewing of the total lunar eclipse! It was a gorgeous night. At moonrise we had crystal clear skies as we watched the already partially eclipsed full moon rise over the Big Belts. As always, it was amazing to see how fast the moon clears the mountain. Of course what we are really seeing as we watch the moon rise is our own Earth's rotational speed as we rotate east. Over the next half an hour or so we watched the moon move deeper into the Earth's shadow. There we were actually seeing the Moon's eastward rotation around our Earth--something we never get to see.
Totality brought its own delight to the night. The moon was a deep, beautiful red. If we could be standing on the lunar surface facing Earth during an eclipse, we would see the Earth in a ring of the same color--almost as if we were watching every sunset in the world at the same time.
The moon was also so much dimmer than normal that through the telescopes we could see stars just past the edge of the moon. The stars are always there but the brightness of the light reflected back to us overpowers all but the very brightest. We were able to witness one fairly bright star appear to emerge from behind the Moon and in a matter of minutes there was a sizable gap between it and the edge--another demonstration of the Moon's rotation around the Earth.
The best thing for me, though, was being able to share the wonder of the total lunar eclipse with others. We got to spend time sharing an amazing celestial event with old friends and new friends including one young astronomer in the 5th grade with his own telescope. I'm sure he will put that telescope and the ones that follow it to good use over the years ahead!
With clear skies, of course.
September 24, 2015
Sunday, September 27, brings us a whopping 4 moons at one time–the Blood Moon, the Harvest Moon, a Super Moon, and a Total Lunar Eclipse! Of course, they all refer to the same moon but each has a special meaning.
The Blood Mood refers to the last total lunar eclipse in a tetrad of 4 total lunar eclipses. This tetrad started on April 15, 2014 and includes the eclipses on October 8, 2014 and April 4, 2015. The next tetrad won’t begin until April, 2032.
The Harvest Moon refers to the full moon in September. Folklore says that this is the Harvest Moon because farmers can work late into the night bringing in the harvest by the bright light of the full moon. Nowadays I’m pretty sure that headlights have taken over that duty!
A Super Moon occurs when the full moon also happens when the moon is at its closest point to the Earth in its slightly elliptical orbit. This Super Moon will be about 225,000 miles from the Earth won’t be this close again until November of 2016. The difference is noticeable in both size and brightness but shouldn’t be confused with the “Moon Illusion” that makes a full moon near the horizon look massively huge. The Moon Illusion really is an illusion–just bracket that huge full moon with two fingers–it will shrink right back to normal size.
Finally, this full moon with be a Total Lunar Eclipse. For us, the eclipse will have already have started at moonrise but totality–when the moon enters the darkest central part of the Earth’s shadow–will begin with the moon nicely above the horizon and will last for an amazing 72 minutes!
To find the time of moonrise for your location, go to http://www.timeanddate.com/moon/ and enter your location.
Moon rise is always a magical moment, and watching one with intent makes it even better!
With clear skies, of course.
July 30, 2015
<Note: Last week's column didn't make the paper so I edited it slightly for this week.>
We are watching Venus and Jupiter continue to drift apart in the early evening western sky. Saturn is beautifully visible in the southwest as night falls. Our second Full Moon in July is Friday the 31st.
The second full Moon in a month is commonly known as a Blue Moon. That definition came into being in 1946 when an article in Sky and Telescope mistakenly stated this as the definition of a Blue Moon. Before then, and still held by some as the "true" definition, a Blue Moon is the third full moon in a season of four. Either way, Blue Moons happen every 2 to 3 years. Conversely, every 19 years there are no full moons in February with January and March both having two Full Moons instead. That will happen next in 2018.
The next big event in our night sky is undoubtedly the Perseids meteor shower beginning in early August. Several factors might make this our best meteor shower in years. During the peak of the shower on August 12th and 13th, our Moon will be just before New Moon so its light will not diminish any of the meteors. Last year's Perseids' were all but drowned out by the "Supermoon" on August 10 which remained nearly full during the Perseids' peak.
In addition, this year we will pass directly through the debris trail of Comet Swift-Tuttle, the parent comet that creates the Perseids. It made its last passage through our solar system in 1992. That intensified the amount of debris left behind and should yield a lot of visible meteors. Some predictions are calling for up to a hundred meteors per hour--something I hope we all get to see!
With clear skies, of course.
July 23, 2015
New Horizons has safely zipped past Pluto and sent home some stunning images of our outermost planet and its moons. A few of those images made the mainstream media and NASA's New Horizon page is the best place to see the rest. You'll find the New Horizons' web site at https://www.nasa.gov/mission_pages/newhorizons/main/index.html. More images are being added all of the time. It will literally take years for all of the data captured by New Horizons to be sent back to Earth.
Closer to home, we are watching Venus and Jupiter continue to drift apart in the early evening western sky. Saturn is beautifully visible in the southwest as night falls. The Moon is at First Quarter on Friday, July 24 and will appear near Saturn until they drop behind the Elkhorns before 2 am.
The next big event in our night skies is undoubtedly the Perseids meteor beginning in early August. Several factors might make this our best meteor shower in years. During the peak of the shower on August 12th and 13th, our Moon will be just before New Moon and it will not diminish any of the meteors. Last year's Perseids' were all but drowned out by the "Supermoon" on August 10 and it remained nearly full during the Perseids' peak.
In addition, this year we will pass directly through the debris trail of Comet Swift-Tuttle. Swift-Tuttle is the parent comet that creates the Perseids. It made its last passage through our solar system in 1992. That intensified the amount of debris left behind and should yield a lot of visible meteors. Some predictions are calling for up to a hundred meteors per hour--something I hope we all get to see!
With clear skies, of course.
July 16, 2015
We are half way through July and at just under a month after the Summer Solstice we can already see that the setting Sun is working its way back south. That also means that the daylight hours are getting progressively shorter by roughly a minute per day this close to the solstice--so we now have almost a half hour less of daylight than we did on the Solstice.
Increasing darkness means more opportunity to use a telescope under dark skies. I'll be the first to admit that it is a challenge to stay up late enough to get to dark skies during June and July. It's a good thing there is still plenty to see during the early evening!
Venus and Jupiter are still fairly close together in the early evening western sky and on the 17th and 18th will be joined by a very thin waxing crescent Moon--don't forget to look for Earthshine on that sliver of a Moon.
Saturn remains high in the southern sky and by 10pm is quite a nice target for even a small telescope. The Broadwater School and Community Library has such a telescope available for checkout to anyone with library privileges, and it is more than capable of showing off the rings of Saturn, Jupiter's four Galilean moons, brightly lit Venus and the always wonderful crescent Moon. Later around 3am you could take that StarBlast telescope and simply pan through the Milky Way to see countless galaxies and nebulas--its wide field of view makes it an excellent tool to simply get lost in the ribbon of stars stretching from the northeast to the southwest.
With clear skies, of course.
July 9, 2015
The New Horizons space probe will flyby Pluto on July 14 at about 5:49 am MDT. On July 4 those of us watching the mission had a scare when the probe's autopilot computer detected an anomaly, switched to the backup computer, and entered "safe mode". This caused a 2 hour break in communications, and an immediate scramble to determine what had happened and what, if anything, could be done to restore the science mission. One big part of this is the sheer distance New Horizons is from home--it takes radio signals 4.5 hours to reach the probe, and another 4.5 hours for anything the probe sends back to reach us. A 9 hour round trip with less than 10 days until flyby means you don't get very many chances to ask questions! Fortunately a part of mission planning learned over the years is to have the spacecraft begin sending diagnostic telemetry back home as soon as communications have been re-established. It didn't take long to determine that the issue was a software timing glitch in a procedure that will not be run again so it was safe to instruct the craft to return to normal operations on July 7.
Of course, I am writing this before that "return to normal operations" has actually happened. Even if New Horizons has other problems after that point, it will flyby Pluto at 30,800 miles per hour. And even if that somehow fails the images and other data we've already received from New Horizons are better than anything we have to date from Pluto and its moons.
Closer to home, Venus and Jupiter remain visibly together in the early evening western sky. Jupiter is now 51 light minutes away from Earth, and Venus is just under 4 light minutes away. Saturn, now at 80 light minutes away, continues shine in the southern sky all night long. The Moon will be past Last Quarter and heading toward New Moon on July 15. It is not even 2 light seconds away yet I'll wager that many of us remember vividly hearing that 4 second round trip delay as we listened to Neil Armstrong on July 20, 1969 radio home from Tranquility Base. Apollo 11's landing site in the Sea of Tranquility is easily located with a small telescope, especially when the Moon is in its waxing crescent phase as it will be on this year's 46th anniversary of the first manned moon landing.
With clear skies, of course.
July 2, 2015
Although the tightest pairing of Venus and Jupiter we saw on June 30 and July 1 has passed, both planets remain close together in the early evening western sky. They will remain relatively close together as both get too near the Sun to see and they transition from the evening sky to early morning sky in August.
Saturn continues to be prominent in the southern sky and is visible all night long. If you are out near midnight, look directly over head to see the Summer Triangle. The Summer Triangle is an asterism--a pattern of stars that is recognizable but not necessarily an official constellation. The Summer Triangle consists of three of the brightest stars in the summer night sky: Altair in the constellation Aquila, Deneb in Cygnus, and Vega in Lyra. First time viewers will find a planisphere or a smart phone app a great aid in locating the three vertices of the triangle and their respective constellations.
Pluto is in the news as the New Horizon spacecraft heads toward its July 14 flyby. Space Simulations has released "Pluto Safari", a free app for iOS and Android devices that provides real time information on the New Horizons mission. It's a great app that includes a mission countdown clock, the most recent images sent back to Earth from the probe and other news and a summary of both sides of the "Is Pluto a planet?" argument. There are compelling arguments on each side of this debate. After you read both you have a chance to voice your opinion in an on-line survey. I cast my vote toward "planet"--I think the new criteria to decided whether a body is a planet or not are too restrictive and need to be modified.
Pluto is not visible at all to the unaided eye, in fact, it takes excellent viewing and a large aperture telescope to resolve our most distant planet. My largest telescope ought to be up to the task but I have yet to see Pluto. I'll keep trying, though--there are always new things to see in the night sky.
With clear skies, of course.
June 25, 2015
On June 24th Mercury reached greatest elongation from the Sun and is now rising about 4:30am. Even at this time of the year with our short summer nights Mercury should be visible in the early morning eastern sky.
On the evenings of June 30th and July 1st, Venus and Jupiter will appear less than 1/2 degree apart in the early evening western sky, culminating a celestial dance that began months ago. Although Venus and Jupiter appear very close together in our evening sky, they are not physically close at all. Venus is about one half Astronomical Units (AU) from the Earth while Jupiter is over 6 AUs away. One AU is the mean distance of the Earth to the Sun, about 93 million miles. They appear close together in the sky because they are aligned in roughly a straight line with the Earth.
At this amount of separation Venus and Jupiter will both be visible in the field of view of a low power telescope and should be quite the sight. Venus will appear as a brilliant half disc and Jupiter should show cloud bands and all four of the Galilean moons.
July 1 also marks the first of two Full Moons in July, rising at 8:42pm and clearing the Big Belts a little before 9pm. With a lineup like this, I would like to invite you all out for a public viewing on Wednesday, July 1st at the Wildlife Management Area at the end of South Ray Creek Road beginning at 8:30pm. As always, check the starhouse-observatory.org web site for last minute updates in case the weather doesn't cooperate. We should be able to watch Full Moon rise, see the Venus/Jupiter pairing, and even Saturn.
With clear skies, of course.
June 18, 2015
Summer arrives with the solstice on Sunday, June 21st at 10:39 am. If you watch the sun set in the west on Sunday night you will see it set at it's farthest point to the north this year. Solar activity has been low but there are a few sunspots visible with, and only with, a properly filtered telescope. I have such equipment and will hold a public viewing soon during this time of long hours of daylight.
Two great resources to see what's happening on the Sun are CalSky (http://www.calsky.com) and SpaceWeatherLive.com (http://www.spaceweatherlive.com). Both have real time displays of the current sunspots. I find CalSky to be more accessible for the public while SpaceWeatherLive tends to focus more on hard data from the various solar observing satellites in orbit around the Sun. Both also have general predictions about possible aurora activity. Our geomagnetic latitude is 53.8 degrees but we are still considered to be in the middle latitudes.
The Sun played a major role in one of the most amazing things I've observed in a long time. On Sunday June 14 at 6:43pm I was able to see the International Space Station cross the disc of the Sun. CalSky had alerted me to this transit several days in advance with an e-mail alert. From that point on all I could do was make sure my gear was all in good working order and wait, hoping for clear skies at that special moment. And we had them! At 6:43:28pm I watched the ISS cross the solar disc in a little over 1 second. It is a wonderful sight to watch the ISS transit at night but a daylight transit of the Sun means that we can see it as a silhouette--the "H" shape of the solar panels are clearly visible. As the elation of seeing the transit ebbed a little, I reflected on all of the things that have happened over the course of human history that enabled me to see this, from Galileo's first use of the telescope to observe the heavens above, to Newton's invention of the reflecting telescope that I use, to the invention of the Baader AstroSolar film filter that provides an inexpensive crystal clear white light image of the Sun. Then there are all of the events that went into making, launching, and staffing the International Space Station. Truly we stand on the shoulders of giants when we safely watch the ISS transit the sun.
With clear skies, of course.
June 11, 2015
Clear skies are returning bringing heat during the day and for our short nights clear, dark skies. And short the night is. Civil twilight is defined as beginning one half hour before sunrise and ending at sunrise for morning and for evening beginning at sunset and ending one half hour later. Astronomical twilight is roughly three times longer--until evening twilight is over the skies are not really dark enough to telescopically observe in good detail any of the deep space objects. In this second week of June, astronomical twilight ends at nearly 11pm and begins again about 3am.
One interesting aspect of this is observing the International Space Station. Because the ISS must be lit by the Sun for us to see it transit, we don't see it if it's more than an hour and a half after sunset or more than an hour and a half before sunrise. But this time of year those two windows overlap. Almost every time the ISS's orbit takes it over Montana we will be able to see its passage.
Venus and Jupiter are still drawing closer together in the evening skies. The Moon will be at New Moon on Tuesday, June 16. Saturn is just past opposition so is still rising in the early evening and is visible all night.
The Sun has had some minor storm activity recently making it more likely we'll be able to see the aurora borealis but even with a major storm we probably wouldn't be able to see those magical northern lights until after midnight.
With clear skies, of course.
June 4, 2015
These are the times that try an amateur astronomer's soul. We've been in a cycle of cloudy weather for a couple of weeks now and according to the NWS forecast more of the same is on the way. Fortunately, some of those clouds are bringing rain to at least part of Broadwater County and we do enjoy watching the afternoon thunderstorms roll over the Elkhorns and up toward Confederate Gulch or down the Missouri. A few evenings I've been lulled into setting up the telescope out on the deck to wait for dark only to hastily drag it back inside just in time to avoid a wall of rain.
Last Monday early in the morning I was able to spot the nearly full moon through the clouds. Because of the tilt of the Earth the Moon's nightly arc across the sky is now low in the south while the Sun's arc across the sky is high. The Sun and the Moon are on opposite sides of the sky and weave that low and high dance across the course of the year. We are less than three weeks away from the Summer Solstice when the Sun will reach its highest and most northward points and then begin again drifting lower and more southerly while the Moon climbs until they meet again at the Autumnal Equinox.
Venus and Jupiter continue to get closer in the early evening sky. By the end of the month they will be very near together. Saturn is rising before dark and is visible all night long. The Moon will be at Last Quarter on Monday so dark skies will return for a few hours each night. We are coming into the best time for us to view the Milky Way in all its summer splendor. From here it appears to be a river of stars falling into a river of water.
With clear skies, of course.
May 28, 2015
We had a fine observing session on Friday, May 22nd. The weather cleared just as as twilight deepened and the Moon, Venus and Jupiter all made excellent viewing. Venus is at the point in its orbit where through the telescope it clearly shows that it is half in light, half in shadow, looking much like our Moon at first and last quarter. The cloud bands and all four of Jupiter's Galilean moons were visible. As I'd hoped, the Moon was stunning with Earthshine illuminating the shadow side and the terminator slicing through some very impressive mountain peaks. Clouds in the east prevented us from seeing Saturn.
Saturn is now just past opposition so we are entering Saturn's prime observing time. Opposition means that it is directly opposite the Sun as seen from the Earth. It is now closest to us for the year. Saturn's rings are nicely tilted and with good seeing conditions even a small telescope should clearly show the gap between the rings and the planet and a larger telescope will show a few of Saturn's moons. With the unaided eye, look for Saturn and the waxing gibbous Moon together about an hour before dawn on Sunday and Monday.
With clear skies, of course.
May 21, 2015
As dark approaches on Thursday look for the 4 day old crescent moon hanging near Venus in the west. If we are fortunate enough to have clear skies--something we've had all too few of lately--the Moon will be fully illuminated with a thin bright crescent directly lit by the Sun and the rest of the lunar disk facing us lit by light reflected from the Earth back to the Moon. Leonardo da Vinci is credited with first explaining this in the early 1500's when he realized that the Earth and Moon reflect light at the same time. The light illuminating the shadow side of the Moon is reflected from the Earth to the Moon and then back to the Earth. And it's a lot of light. Because the Moon's phase and Earth's phase as it appears from the Moon are mirrored images when we see a thin crescent Moon from Earth, from the Moon we would see a nearly full Earth.
The Earth reflects roughly a third of the light that strikes us from the Sun, so we have a reflection coefficient, or albedo, of 0.3. The Moon has an albedo of 0.12, less than half of the Earth's, yet we all know that the full moon is bright enough to cast sharp shadows and wash out most of the night sky.
The crescent Moon is another of my favorite things to observe. Shadows in the light side are long and dramatic and the terminator--the boundary between light and dark--is sharp and crisp. Tall mountain peaks near the terminator are brightly lit with the mountain below still in shadow.
As I write this, the forecast for the weekend is marginal but I'll be hosting a public viewing session on Friday, May 22nd at the Wildlife Management Area at the end of Lower Ray Creek Road. I'll be there at 9pm. We'll be able to see the crescent Moon, Venus, Jupiter and Saturn plus some deep space objects. Check starhouse-observatory.org for last minute weather updates and for directions to the site. I hope to see many of you there!
With clear skies, of course.
May 14, 2015
With Clear Skies
Jupiter and Venus are drawing closer together in the early evening sky through the rest of May. Jupiter is high in the southwest sky in the early evening, setting behind the Elkhorns around 2 am. Saturn rises around 9 pm and is visible all evening. The Moon is in its waning crescent phase and will be at New Moon on Sunday the 17th.
Even with New Moon on Sunday, and the dark skies that accompany it, visual observing is becoming limited this time of year. Summer solstice is still 5 weeks away but we can already see how much shorter the night is. We really aren't fully dark now until after 10pm and by 5am we are into morning twilight.
When you step out after dark and look north, the Big Dipper is visible. Unlike during the winter months, the "dipper" is pointed down, as if pouring water onto the Little Dipper and Polaris, the last star in the Little Dipper's handle. Polaris is our North star--it is very close to the true North Celestial Pole and marks the axis around which the night sky appears to rotate.
With clear skies, of course.
Jeff Ross
Star House Observatory
http://www.starhouse-observatory.org
Questions? Comments? jross@starhouse-observatory.org
May 7, 2015
Venus remains the brightest object in the early evening western sky this week. In a telescope, Venus is still in its gibbous phase but as May progresses it will become a thinner and thinner crescent. Mercury should be visible low over the Elkhorns at dusk but might be too low for us yet. It will be easier to spot in the coming weeks. Jupiter is high in the sky and nearly due south in the early evening, setting behind the Elkhorns around 2:30 am. Saturn rises about dark and is visible all evening. The Moon is in its waning gibbous phase and will be at Last Quarter on Monday.
We are getting more warm evenings now and that makes it much nicer to stay out observing, even if it doesn't get really dark until 10pm. Here are some tools that can make finding things in the night sky much easier. The classic low technology method is a planishere for locating stars and constellations. These are available on-line through Sky and Telescope or Amazon for about $11. My favorite is the one called "The Night Sky" by David S. Chandler. For our latitude of 46.38 degrees north you'll want the version that covers the 40 - 50 degree latitude range. This is the planisphere that comes with the StarBlast telescope available on loan from the Broadwater School and Community Library.
A planisphere is like a road atlas to the night sky, and like a map it is great for giving you the big picture of the entire night sky, making it easy to see how the constellations fit together.
Higher tech tools are also available. My favorite is the iOS/Android/Kindle app called Star Walk. Just point your phone at the sky. Star Walk will use the phone's internal sensors to determine where you are on the planet and the angle you are holding the phone and show you precisely what is in that spot in the sky. That makes it much easier to identify what that bright star is over there near Venus, or if that dot near the horizon is Mercury or a star.
Whatever tools you chose, the night sky is full with amazing things waiting for you to see and identify.
With clear skies, of course.
April 30, 2015
With Clear Skies
Venus remains bright in the western sky in the early evening this week. Jupiter is high in the sky and nearly due south in the early evening, setting behind the Elkhorns around 3am. Saturn rises around 10pmand by dawn is almost directly due south. The moon is in its waxing gibbous phase and will be full on Sunday.
That big, bright moon plays a major role in the rest of what's happening during the coming week. The eta Aquariids meteor shower will peak on Sunday May 5th and Monday, May 6th. The name refers to the radiant point of this meteor shower. As you watch a meteor streaking across the sky at night, follow the trail back and you'll see that it appears to originate near one of the the brightest star in the constellation of Aquarius. The eta Aquariids are dust and small debris that separated from Halley's Comet hundreds of years ago. Earth passes through this stream of dust left twice a year, the eta Aquariids in early May and the Orioinids in late October.
This year the nearly full moon will make it hard to see any meteors but it's always worth the effort. The best time is early in the pre-dawn morning--dress warmly and use a reclining deck chair near a building to block the Moon. Some of the most notable meteors you might see are called Earthgrazers--they parallel the horizon and are traveling relatively slowly with a long tail.
The Moon might spoil the eta Aquariid's display this year but weather permitting I will be celebrating full moon rise with a public viewing Sunday evening at the Wildlife Management Area at the end of Lower Ray Creek Road. Moon rise is at 8:21pm but we won't actually be able to see it rise over the Big Belts until 8:45 or so. Check starhouse-observatory.org for directions and any last minute weather updates. I hope to see many of you there!
With clear skies, of course.
April 23, 2015
Venus continues to dominate the early evening western sky this week. Mars is now dropping behind the Elkhorns too early in the evening for us to see. By late May it will be rising in the early morning and be visible once again. Jupiter is high in the sky and nearly due south in the early evening, remaining visible all night long. Saturn rises before 11pm and by dawn is almost directly due south. The moon is in its waxing crescent phase and will be at first quarter on Saturday.
Orion is in the southwest sky with the belt nearly horizontal to the horizon. The three stars of the belt point left at Sirius, the brightest star in the night sky, and point right at Aldebaran and the Pleiades.
We had a good turnout at our first public observing session last Friday night. It was a beautiful night, with still, transparent skies providing some of the best observing we've had this year. Jupiter was a favorite of the night, with all four Galilean moons and the bands on Jupiter clearly visible. Orion's Nebula was also a treat and we were able to see Comet Lovejoy and the Andromeda Galaxy. Right on schedule the International Space Station made its transit overhead at 9:47pm.
Carroll College will be hosting its annual Astronomy Day this coming Saturday, April 25 beginning at 11am, with talks and presentations scheduled over the course of the day. Carroll also owns a solar telescope so it's a perfect time to see the sunspots and flares on the sun.
With clear skies, of course.
April 16, 2015
Venus continues to dominate the early evening western sky this week. Mars is now setting a little over an hour after sunset so look for it very low over the Elkhorns around 8:30 pm. Jupiter is high in the sky and nearly due south in the early evening, remaining visible all night long. Saturn is now rising around 11pm and by dawn is almost directly due south.
We will have a New Moon this Saturday so I'd like to invite anyone interested to join me for a public observing session on Friday, April 17th beginning at 8:30 pm. I'll set up two telescopes at the Wildlife Management Area at the end of Lower Ray Creek Road. As I write this the long range forecast for Friday evening looks promising. We'll be able to see many of the objects I've been writing about, including Venus, Jupiter, Orion's Nebula, the Andromeda Galaxy, and possibly Comet Lovejoy. To top the evening off, there will be a pass of the International Space Station and the Dragon re-supply ship at 9:47 pm!
I'll post an updated announcement about the event and full directions to the viewing site on starhouse-observatory.org so please check there if there's any doubt about the weather cancelling the viewing. I hope to see many of you there!
With clear skies, of course.
April 9, 2015
Venus and Mars continue to drift apart in the early evening western sky this week. Mars is now setting a little over an hour after sunset so look for it very low over the Elkhorns around 8:30 pm. Jupiter is high in the eastern sky over the Big Belts in the early evening and remains visible all night long, hanging over the Elkhorns in the morning before sunrise. Saturn is now rising before midnight and by dawn's twilight is almost directly due south.
The Moon is in its waning gibbous phase and will be at last quarter on April 11th, rising around 2am.
Even though we think of Orion as a winter constellation it remains very visible in the early evening throughout April. Orion's belt is now almost horizontal to the ground, pointing left to Sirius and right to Aldebaran, Venus and the Pleiades. Sirius is the brightest star visible in the night sky but it is still no match for Venus.
The International Space Station is also visible in the evening this coming week--be sure to see NASA's Spot The Station web site for an list of the times.
With clear skies, of course.
April 2, 2015
"Being country bred, I am at ease in darkness" -- Mary Oliver
I, too, am at ease in darkness. As I write this I've just returned from a work related conference in New York City, a place where there is no darkness.
Most of the time I was there we were under grey damp and dreary skies but the last night we got a break in the clouds and I was able to see the first quarter Moon through the Manhattan skyline. But that is all I could see in the night sky. Here at home under a similar Moon the stars and planets are diminished but still visible. In New York there is simply too much light at night.
There is growing concern world wide about the diminishing night sky. Even here where we still have relatively dark skies, night glow is visible on our horizon from Helena, Great Falls, and Bozeman. Not only is this a concern to those of us who enjoy the night sky and viewing its wonders, increasing night light pollution is known to have a profound impact on the migration of birds and other wildlife.
One of the biggest organizations spearheading the struggle to preserve our night skies is the International Dark Sky Association (www.darksky.org). They have an abundance of resources available, covering everything from if we should light at night and where we must how to do so properly, the promise and problems of LED lights, especially as cities begin to switch to LED street lights and to the impact improper lighting has on wildlife and even on our own health.
There are even opportunities for citizen scientists to participate in mapping the actual quality of the night sky by using smartphone apps to photograph and analyze the night sky wherever you might be. For iOS devices, look for Dark Sky Meter ($0.99) or for Android devices look for Loss of the Night. Data from these apps are automatically uploaded to a central database.
Saturday night we will be under the natural light of a full moon, dominating the night sky for a few nights but the natural cycle of the Moon's rotation means that our dark skies will return and we will be able to see all the wonders of the visible universe again.
With clear, and dark, skies, of course.
Jeff Ross
Star House Observatory
http://www.starhouse-observatory.org
March 26, 2015
Venus and Mars continue to drift apart in the early evening western sky this week. Jupiter is high in the eastern sky over the Big Belts in the early evening and remains visible all night long, hanging over the Elkhorns in the morning before sunrise. Saturn rises before 1 am and by 6am is almost directly due south. The Moon is just past first quarter on Thursday and will be directly above Orion after sunset. With our warmer evenings, now would be a great time to check out the telescope from The Broadwater School and Community Library to observe the Moon, Orion's Nebula, Jupiter and its four Galilean moons and many other early evening delights.
Usually I write about upcoming events but this week I'd like to mention two separate events that we missed, in hopes that we will have better luck next time.
On March 17, St Patrick's Day, we should have been able to see a stunning display of the aurora borealis--the northern lights--except that we were actually under low clouds and getting a half inch of much needed rain. Even I won't begrudge missing this event for rain after our long dry winter. The events leading up to this display began a full day before when a smallish flare on the sun shot out an average Coronal Mass Ejection. A CME is a burst of hot solar plasma wrapped in a magnetic field. They travel much slower than light and can take up to 24 hours to reach us.
This CME also happened to be Earth directed but not all are. We knew that this CME was likely to strike at least a glancing blow to our Earth's magnetic field but all evidence suggested it would spark a weak, minor geomagnetic storm. Instead it actually became the strongest geomagnetic storm of this 12 year solar cycle--sending the northern lights visible far to the south of us.
Because ground and space based sensors can detect advance particles preceding the actual CME's arrival it is possible to sign up for e-mail or text alerts that can provide up to 4 hours notice that a solar storm is approaching. Several are subscription based and cost around $5 a month but there are two free ones I know of and one more coming soon. SpaceWeatherLive.com and CalSky.com both have free e-mail alerts. SpaceWeatherLive's alerts are generic while CalSky uses our location to better fine tune the alerts. There is also an aurora detection network in Montana. The detector network consists of multiple observation sites and is fully operational but the alerting service is not quite on-line yet. This will be our best resource for real time aurora alerts when it becomes available.
The other event we probably missed was catching a glimpse of an hours old Moon on Saturday March 21 in the early evening. The Friday before marked the new moon, a total solar eclipse, and the vernal equinox. Helena observers reported seeing "the thinnest crescent Moon ever" and indeed, the Moon they were seeing was not even 16 hours past new. I had been out looking for this as well but clouds over the Elkhorns prevented any chance of seeing it.
We can only hope for better luck next time!
With clear skies, of course.
Jeff Ross
Star House Observatory
http://www.starhouse-observatory.org
March 19, 2015
This week Venus and Mars continue to drift further apart in the early evening western sky. Jupiter can be found high in the eastern sky over the Big Belts in the early evening and remains visible all night long, hanging over the Elkhorns in the morning before sunrise. Saturn rises around 1 am and by 6am is almost directly due south.
Friday is a magical day with the new moon, a total solar eclipse and the vernal equinox all happening within the span of 13 hours. It must be a new moon for a solar eclipse to occur but they happen only about twice a year. This will be the only total solar eclipse in 2015. Unfortunately for us it will not be visible in this part of the world at all. It will start as a partial eclipse over far northern Europe reaching totality over the Svalbard Islands of Norway, the Faroe Islands of Denmark and a strip of the Arctic Ocean. March in the north arctic is a poor time for clear skies but eclipse chasers are sure to be in the path of totality hoping to catch a glimpse.
The vernal equinox marks the first day of spring, even though it seems like it's been spring here for a couple of weeks already this year. Our weather is only loosely coupled to the vernal equinox. As I recall last year at this time we'd just finished digging out from a pretty good blizzard! An equinox is also said to be the day when there is an equal amount of light and dark but that is not true either. That day is properly called the equilux and always occurs a day or two before the spring equinox and after the fall equinox. Properly, the equinox marks the day when the plane of the Earth's equator passes the center of the Sun and the 23.5 degree tilt of the Earth is neither inclined toward or away from the Sun.
That tilt can be seen as the point on our local horizon where the sun climbs above the Big Belts at sunrise and drops below the Elkhorns at sunset. In winter that point is far to the south, in summer far to the north. We are at the midpoint in that arc on Friday, the day of the vernal equinox.
Step out at either sunrise or sunset on Friday and mark the spot on the horizon where the sun rises or sets. As we head into summer that point will shift toward the north until the summer solstice then it will begin marching back south. Next September 23 on the autumnal equinox the sun will be at exactly the same point on the horizon as it is on this Friday, March 20. How lucky we are to live in a place where we can witness this arc of the sun over the course of the year!
With clear skies, of course.
Jeff Ross
Star House Observatory
http://www.starhouse-observatory.org
March 12, 2015
Venus and Mars continue to highlight the early evening western sky. Look for bright Venus high in the west at dusk while north and closer to the horizon is Mars. Mars now sets a full hour before Venus.
Jupiter can be found high in the eastern sky over the Big Belts in the early evening and remains visible all night long. Saturn is now rising after 1 am and will make a nice pairing with the waning gibbous moon early Friday morning.
These planets are all relatively bright and can easily be seen with the unaided eye but in the next week we will have the chance to see the second brightest object in the night sky--brighter than Venus but not as bright as the moon--the International Space Station!
The ISS began construction in 1998 and has been continuously occupied for over 14 years. It is the largest artificial satellite in Earth orbit and circles the Earth every 90 minutes. Because the orbit is at an inclination of 51.6 degrees not all passes are visible to us but quite a few are, always in the hour or two after sunset and before sunrise.
We will be able to see the ISS every early morning for the next week. The easiest way to get the times for our Broadwater area is to go NASA's Spot The Station (http://spotthestation.nasa.gov) web page. There you select our location by choosing United States, Montana and Helena in the form. The chart that is displayed shows not only when to look but where and how long the ISS will be visible.
Step out into the early morning a minute or so early and look out to the west. The ISS will appear right on time and might look like a high flying jet but it moves much faster. As it arcs overhead, give a thought to the six people aboard, three Russians, two Americans and one Italian and imagine what they might be seeing as they look out the observation window and down over Montana as the ISS races into the sunlight.
With clear skies, of course.
Jeff Ross
Star House Observatory
http://www.starhouse-observatory.org
March 5, 2015
Each day Venus and Mars move further apart in the early evening western sky. Look for bright Venus while to the north and closer to the horizon is Mars. Two weeks ago Venus and Mars dropped behind the Elkhorns at about the same time. Mars now leads the way by 30 minutes.
Jupiter can be found high in the eastern sky over the Big Belts at twilight and is visible all night long. Saturn is now rising at 1 am and is best seen in the early morning just before sunrise.
The moon is full Thursday night, rising over the Big Belts about the same time as the sun sets over the Elkhorns. The full moon is a problem for most of observational astronomy--it is so bright it washes out many of the stars and deep space objects and even the detail we might see in the planets.
Yet I look forward to the full moon every month for the chance to see two different events. The more rare of the two is an eclipse of the moon. We will have the opportunity to see two here this year--next month's full moon will have a partial lunar eclipse where the moon is not completely in the earth's shadow and in September we might see a total lunar eclipse.
The other special event is simply the moonrise over the Big Belts. You can see exactly where it will rise as a bright oval behind the mountain for minutes before it actually appears. With a telescope, a spotting scope, or a pair of binoculars there will be enough light to show trees swaying in the wind. As we get closer and closer to moonrise, that oval gets bigger and brighter until suddenly you can see the edge of the moon itself. I find myself holding my breath as I watch moonrise unfold. The whole process takes only 2 magical minutes.
With clear skies, of course.
Jeff Ross
Star House Observatory
http://www.starhouse-observatory.org
February 26, 2015
Venus and Mars remain close together in the early evening western sky but have now traded places. Look for bright Venus. Nearby and slightly to the north is Mars. Over the coming week the separation between the two will continue to increase.
The moon is at first quarter now, rising around noon and high in the southern sky in early evening. Half of the lunar disk facing the earth is now illuminated by the sun.
Jupiter continues to be visible all night long; over the Big Belts in early evening and by early morning hanging over the Elkhorns. Saturn rises a little earlier each day and is still best seen in the early eastern morning sky.
Five of the planets in our own solar system are easily visible to the unaided eye. The furthest of those is Saturn but on the scale of the universe it is in our own back yard. The common measure of speed and distance in astronomy is based on the speed of light at 186,000 miles per second. Light from the sun to our earth takes just over 8 minutes to arrive but it takes almost 80 minutes to reach Saturn.
The most distant object visible to the unaided eye is the Andromeda Galaxy. When we step out into a dark, moonless night and find the Andromeda Galaxy our eyes are catching photons that left there 2.5 million years ago. Our earth was in the beginning of the Pleistocene--before the first of the ice ages. We are looking back into time.
With clear skies, of course.
Jeff Ross
Star House Observatory
http://www.starhouse-observatory.org
February 19, 2015
This week Venus and Mars make a lovely pair in the early evening western sky. Look for bright Venus. Nearby and slightly to the south is Mars. As we head into the weekend the pair is joined by a waxing crescent moon making an easy to spot triangle.
Jupiter dominates the early evening eastern sky and is visible all night long. Look out over the Big Belts for our largest planet. By early morning it can been seen hanging over the Elkhorns to the west.
Saturn rises a little after 2 am and is best viewed in the east just before morning twilight.
Orion is due south in the evening--look for the iconic "belt". Orion's "sword" hangs from the belt on the east side and contains one of my favorite of all deep space objects, Orion's Nebula. A small pair of binoculars will show some luminosity and detail in the massive star forming nebula but to get a real appreciation you must use a telescope.
Don't forget that anyone with library privileges can check out an easy to use reflector telescope from the Broadwater School and Community Library! The StarBlast telescope comes with everything you need to see much more detail in the nebula, as well as Jupiter's largest four moons and the rings of Saturn.
With clear skies, of course.
Jeff Ross
Star House Observatory
http://www.starhouse-observatory.org