How does Halloween have its roots in astronomy? How smooth does the surface of the primary mirror in an MRO Interferometer telescope have to be? Who is that new guy we’ve seen around New Mexico Tech’s Department of Physics, and what does he have to do with MROI?
You can find out the answers to all of these questions and more in the MRO Department of Outreach and Communications’ monthly newsletter. The October issue of the MRO Inquirer, which features articles about the topics above, will be sent out to members of the Friends of MRO at the end of this week; early and direct delivery of MRO’s monthly newsletter is one of the perks of membership. If you’re not a member of our Friends group yet, don’t despair – our newsletters are released to the public in the middle of each month.
We kindly ask that you consider becoming a Friend of MRO and support the work the MRO Outreach team is doing. Along with publishing a monthly newsletter, the Outreach Department produces the Astro Daily articles and is active on all social media platforms, sharing our love of astronomy with the local community and beyond. While our monthly public star parties and seasonal observatory public tours are on hold due to COVID-19 restrictions, we expect to be able to offer virtual streaming star parties and observatory tours in the near future. Your membership contribution would help support these endeavors, and make you a vital part of our mission to develop education and outreach programs, and to expand the frontiers of astrophysical research.
If you are interested in learning more about Friends of MRO, please follow this link.
Today I’d like to give a shout out to one of my favorite astronomy writers and educators, the self-dubbed “Bad Astronomer” Phil Plait. Tomorrow is Phil’s birthday, so warm birthday wishes are in order. If you’re not familiar with Phil, read on!
Phil started his career in astronomy as an avid amateur, observing the night sky with his own telescopes. He went on to earn a PhD in astronomy from the University of Virginia (UVa) in 1994, where he also taught beginning astronomy courses and astronomy labs. He branched out into public education by holding Public Nights at the UVa’s observatory, where he honed his skills of interacting with the public and answering their questions about astronomy. In his Education and Public Outreach role for the Physics and Astronomy department at Sonoma State University, he worked on a variety of NASA-sponsored public outreach programs including those for the Gamma Ray Large Area Space Telescope and XMM-Newton. He went on to work on NASA’s Space Telescope Imaging Spectrograph (STIS) to help calibrate the STIS by analyzing test images to determine its level of functioning. He is well known for his website “Bad Astronomy” (ca. 1999 – 2006) where he debunks some of the misinformation that runs rampant on the internet, and, as he puts it, “…airs out myth and misconceptions in astronomy and related topics”. He has authored three popular books on astronomy, has appeared on multiple documentary series, and currently writes an extremely entertaining and informative blog.
On the subject of “Bad Astronomy”, I come across many examples in the media fairly frequently. Most recently, I read an article about Saturn being well-placed for observations during August, having reached opposition in late July. I have no complaints about the contents of the article, it was all good information. But the header image they used for the article is a different matter! Someone (I’m betting some design staff, not the author) chose a striking graphic of a fictitious rocky planet with rings and a bunch of moons from Shutterstock rather than use an actual image of Saturn. Don’t get me wrong, it’s a very cool graphic. My problem with this kind of depiction is that there could be folks out there who think they are looking at an actual image of the gas giant Saturn, rather than an artist’s conception of a ringed planet with a rocky surface. Perhaps I’m just splitting hairs, but for me this misleading graphic puts a stamp of “misinformation” on an otherwise nice article. You can see it yourself at this link.
I’ll share some other examples of bad astronomy and misinformation in future posts. Until then, I encourage you to check out Phil Plait’s old website Bad Astronomy and his new Bad Astronomy blog, I think you’ll be glad you did!
M. Colleen Gino, MRO Assistant Director of Outreach and Communications
Last month in our Comet Hunter article we talked about some of the opportunities for we astronomy buffs to contribute to some real science projects by becoming citizen scientists for NASA and other organizations. Today I’d like to highlight one of my favorite projects, Zooniverse’s Galaxy Zoo. If you’re good at distinguishing subtle shapes and faint features in fuzzy blobs, then this may just be the project for you!
More than one million folks worldwide have contributed to people-powered research projects offered by Zooniverse. One need not have any specialized training or knowledge to become a part of the Galaxy Zoo team, just the ability to access the Galaxy Zoo website and have a decent computer monitor with a good enough view of the galaxy images to make some feature determinations.
Today’s Galaxy Zoo is a spin off from a galaxy classification project initiated by the Sloan Digital Sky Survey (SDSS) team back in 2007. The SDSS dataset was huge – it contained images of over 100 million galaxies – and would have taken the team scientists alone far too long to sift through. Then they had the idea to engage the public in sifting through the data with hopes of relieving the project scientists from doing some of the more straightforward galaxy classification work. They were pleasantly surprised at the result; over 50 million galaxy classifications were submitted by the 150,000 citizen scientists working on the project in the first year. This meant that each galaxy in the survey had classifications submitted by multiple individuals, which was the perfect measuring stick to determine the accuracy of the classification – majority rules.
Since that first round over a decade ago that focused on SDSS data only, the project has included data from a myriad of sources, from the Hubble Space Telescope to the UK Infrared Telescope. The current iteration of the project contains data from the Dark Energy Camera Legacy Survey (DECaLS). DECaLS is ten times more sensitive to light than that the SDSS instruments were, so the current images contain much more detail than the first images did.
Similar to the NASA Citizen Science Projects, the Zooniverse offers projects in many scientific disciplines beyond astronomy. If Galaxy Zoo doesn’t sound like the right project for you, check out the Zooniverse project page as well as our Comet Hunter article for other ideas on how to take part in some cutting edge research and contribute to real scientific discoveries.
M. Colleen Gino, MRO Assistant Director of Outreach and Communications
People around the world are buzzing with the latest news to come out of the world of astronomy: scientists have just announced that phosphine has been detected on Venus. Ok, so admittedly this doesn’t sound like such Earth shattering news, so what’s the big deal? Well phosphine, like oxygen, is a sign that scientists look for as a possible indication of the presence of life. This is because, as far as we are aware, the only natural process that could account for the amount of phosphine found on Venus would be the decaying of organic matter – life would have to be present on Venus.
Scientists first discovered the phosphine signature on Venus by using a submillimeter radio telescope to observe the planet. When the signature was detected, they enlisted the help of a much more sophisticated radio telescope to confirm their initial findings. The Atacama Large Millimeter/submillimeter Array (ALMA) is also an interferometer; however, where the MROI is an optical interferometer, ALMA is radio and therefore views light in the radio spectrum. You may be familiar with ALMA and the shape of its winding road from a previous article. ALMA was able to confirm what scientists had been hoping was true, a large amount of phosphine was in fact present on Venus.
Now some of you may be aware that Venus’ surface is much too hot and volatile to sustain life, so how can this be? Were we wrong about that in the same way we were wrong about Pluto’s status as a planet? No, Venus’ surface could definitely not sustain life, so don’t go and bin everything you learned about the solar system back in school just yet. The atmosphere, however, has conditions very similar to those found on Earth, and the atmosphere just so happens to be where all this phosphine has been detected. Most importantly, the atmosphere holds droplets of liquid and sits at a relatively comfortable temperature compared to the surface about 50 kilometers below it. Both of these, presence of liquid and a mild temperature, are essential for life to be able to thrive.
So is there anything that leads us to believe that this presence of phosphine might not mean that life flourishes up in Venus’ atmosphere? Of course there are a few facts that may cause doubt. It is true that we have no other reasonable explanation for how phosphine could be present on Venus at the levels it is without the presence of life, but we also know of no living creature that can live in sulfuric acid, which just so happens to be the liquid that is found there. But that doesn’t mean that this isn’t still extremely exciting news. One way or the other, this discovery will lead us to a completely novel discovery about our Universe. Whether that discovery is the existence of life outside of Earth, or a previously unknown natural process that yields phosphine remains to be seen. But the next time you’re looking at the sky at night, look for the second brightest object after the moon. That’ll be Venus. She’s our closest planetary neighbor in our solar system, and she has something to show us.
Editor’s Note: Venus rises at about 3:40 AM, and is so bright that it can be seen up until about a half-hour before sunrise.
Today is the first day of fall, which means it’s the time of year when the Summer Triangle can be seen nearly overhead at astronomical twilight, when the Sun has dropped below the horizon far enough that the sky is no longer illuminated by any sunlight. If you’ve never heard of the constellation of the Summer Triangle, there’s a good reason for that — the Summer Triangle is an asterism rather than a constellation.
Constellations and asterisms are similar in that they both refer to a recognizable pattern of stars visible to the naked-eye. However, a constellation is more; it is an officially recognized designation that refers not only to the pattern of visible stars but to a well-defined area of the sky surrounding those stars. These areas of the sky are designated by the International Astronomical Union (IAU), the recognized authority responsible for assigning designations and names to celestial objects.
The Summer Triangle is made up of the stars Altair, Deneb, and Vega, the brightest stars in the constellations Aquila, Cygnus, and Lyra respectively. The Milky Way runs through the Summer Triangle, and appears brightest when it is overhead, about an hour-and-a-half after sunset at this time of year.
After you’ve located the Summer Triangle, see if you can find the planets Jupiter and Saturn to the south. Jupiter, which will be about 30°above the SSW horizon should be easy to pick out, since it’s the brightest object in that area of the sky. You can find Saturn about 8° to the left of Jupiter. For a reminder of how to measure distances in the sky using nothing but your own hands, check out this previous blog post.
**Author’s note: Everything written here is true for those who live in the Northern Hemisphere. While some things written here are true for anyone living in the Southern Hemisphere (AKA the land where Christmas happens during summer) the dates will be off by 6 months. Shelbi Etscorn
Fall is upon us! The summer heat is slowly dissipating (thank goodness!), harvests are about to be in full swing, Halloween, falling leaves, and everything that comes with the changing of the season. Tomorrow is often regarded as the official beginning to the fall season, but do you know why? Tomorrow marks the autumnal equinox. So what is an equinox?
You may have noticed that ever since the first day of summer (usually June 21), the days have slowly gotten shorter and shorter. In fact, we’ve every day since June 21 has had about 2 minutes less sunshine than the day before it. Prior to June 21, we were actually gaining the amount of time in the sun by about the same amount each day. This makes June 21 our summer solstice. It is the longest day on Earth for those living in the Northern Hemisphere. December 21 is our winter solstice: our shortest day of the year although these dates may shift a few days depending on the year due to leap years.
On either side of these two days, right in the middle, sit our vernal and autumnal equinoxes: usually March 21 and September 22. It is on these days that everywhere in the world experiences approximately the same amount of daylight hours as nighttime hours. The word equinox actually comes from the Latin word aequinoctium which itself is derived from the words aequus (equal) and noctis (night). Vernal is the Latin word for spring while autumnal is the Latin word for autumn.
In short during the winter and spring season, every day has a little bit more sunlight than the day before, and in summer and fall every day has a little less. Still following me? So why does this happen?
Well to answer that question, you have to know how our planet orbits the sun. You hopefully know that the Earth is constantly spinning and constantly revolving around the sun. But the Earth is actually tilted on its axis about 23.5 degrees. Because of this, different parts of the planet are facing the sun for different amounts of time throughout the year. This is what causes seasons.
Twice a year, the sun finds itself directly above the Earth’s celestial line and perpendicular to Earth’s axis (seen here as a red line). Because of this, all of Earth receives the same amount of sunlight during those days.
The celestial equator is the imaginary line that dissects the Earth into the Northern and Southern Hemispheres and sits above the equator. For two days a year, the sun follows the path of this line as the Earth orbits and spins around it. These days are the equinoxes. Since the Earth’s axis is perfectly perpendicular to the sun on these days, all of the Earth receives the same amount of sunlight.
The autumnal equinox has long been noticed and celebrated by humans. It is especially important as it marks the beginning of the harvest season. Some historians have even speculated that ancient monuments such as Stonehenge were built specifically to align with the sun during the equinoxes. Early calendars were built specifically to account for the equinox and solstices and observations of the lengths of days were the building blocks early scientists used to help us understand the Earth’s place and movements in our solar system.
The days will only get shorter from here until we reach the winter solstice in December, so enjoy the sunlight while you can because after tomorrow, it will more often be night that not!
We are looking forward to a mostly moonless weekend, with the new Moon having just occurred yesterday. Here a just a few things you might look for this weekend if you find yourself outside under the starry sky.
Zodiacal Light– check out our article posted earlier in the week to see what it is and how to find it. ISS Pass – check out our article posted earlier in the week for full details on the International Space Station pass tonight. Galactic Center – check out our article posted earlier in the week for tips on when to view the center of our galaxy before it slips below the horizon for the winter.
Other things to look for are the planets Saturn and Jupiter, visible about 30° above the horizon in the southern sky after sunset. The planet Mars is steadily getting brighter, heading for its close encounter with us on October 13. You can see the red planet Mars about 10° above eastern horizon a couple of hours after sunset. Venus rises in the east in the wee hours of the morning, and by an hour before sunrise it will be about 30° above the horizon. Venus is easy to pick out because it is the brightest object in that part of the sky. If you need a reminder of how to measure distances in the sky, check out our previous article that describes how to measure distances in the sky using your hands.
Enjoy your weekend!
M. Colleen Gino, MRO Assistant Director of Outreach and Communications
Fall is just around the corner, which means cooler days, longer nights, and for those of us in the southwest, clearer skies as the monsoon season draws to a close. This is also the last chance to view our own Milky Way’s galactic center before it sinks below the horizon for the winter.
The Milky Way is a fairly faint and extended object, so you’ll want to wait until it is fully dark (astronomical twilight) to observe. I use the smartphone app LunaSolCal to find when astronomical twilight begins for my location, but this information can be found many other places such as your favorite weather website.
Since any kind of light including moonlight will interfere with your observations, you’ll get your best view from a dark sky site on a moonless night. Tonight the Moon is new, so you have a couple of dark nights before the Moon starts to interfere with your observations.
Now that we know how, when and where to view the galactic center, what is it that we’re actually viewing? As you may recall, the Milky Way is a spiral galaxy composed of anywhere from 100 to 400 billion stars. Seen face on, it probably looks much like one of our neighboring galaxies, the Andromeda galaxy, with discernable spiral arms and a central bulge.
The Andromeda Galaxy.
Simply stated, the galactic center is the center of rotation of the Milky Way. This region of our galaxy contains all manner of astonishing objects from a supermassive black hole four million times the mass of our Sun at the very core, to blazingly hot clouds of gas with temps of millions of degrees. There is also a great concentration of Messier objects in this region of the sky, as illustrated in the sky chart below.
If you can observe from a dark sky site, see if you can pick out the three Messier objects M4, a globular cluster, Ptolemy’s Cluster M7, an open star cluster, and the Lagoon nebula M8, a huge, glowing cloud of gas and dust. Under pristine conditions, all of these are naked eye objects, things you can see without the use of an optical device such as a telescope or binoculars.
So take a look to the south southwest around 8:30 to 9:30 PM over the next two or three nights, to get a last good glimpse of the galactic center before this portion of the Milky Way dances away for the winter.
M. Colleen Gino, MRO Assistant Director of Outreach and Communications
A few days ago I received an email from a friend suggesting that we cover more basic astronomy topics for newbies, as well as suggest objects that can be seen from a light polluted sky for those not able to get to a dark sky site. This got me thinking about my bias to talk about what you can see from a dark sky site since I live in one, as well as my presupposition that most folks reading an astronomy blog are already familiar with astronomy basics. Thanks, Sheila, for reminding me that there are newbies eager to learn more about the basics, and that observing from your light polluted backyard is better than not observing at all! With this in mind, moving forward we will broaden the scope of the topics we cover here on Astro Daily.
Today I’ll talk about observing from your light polluted backyard, with a few astronomy basics thrown in. One of my favorite objects to observe is not a planet or a star, but the International Space Station (ISS). For me, there’s something magical about watching that bright little light traversing the sky and knowing that there are people in that bright little light, working on a science experiment, or eating a meal, perhaps holding their favorite object from home, or maybe settled in for their “night’s” sleep. What would it be like, I wonder, to experience sunrise every hour-and-a-half? That really changes the definition of pulling an all-nighter…
ISS pass while a tiny astronaut looks on. Yes, I have astronaut dolls…
I enjoy observing the ISS so much, that it’s the first topic I wrote about here on Astro Daily. I’ve photographed thirty-four ISS passes in the past five years and observed many more: from the wee hours of the morning to way past my bedtime; throughout all seasons whether clear, cloudy or snowy; and from my own backyard to one of my favorite locations, the Old San Miguel Mission on Christmas Eve.
ISS pass over the Old San Miguel Mission in Socorro, New Mexico, adorned with lumnarias on Christmas Eve.
There are many websites and smartphone apps that tell you when and where to see the ISS pass overhead from your location anywhere on Earth; my favorite is the website Heavens Above, which is also available as an app. After entering your geographical location, you can retrieve information regarding ISS passes which include visibility tables and sky charts. You can also get information on various other satellite passes (such as the Starlink satellites), as well as interactive sky charts, Sun and Moon data, and much more.
Those of us in New Mexico will have a prime viewing opportunity this coming Friday, September 18. On this particular pass the ISS will rise above the horizon early in the evening (about 7:45 PM MDT), will pass high overhead (68° alt), and appear very bright (-3.4 mag) – a perfect object for light polluted backyard observing!
The skymap and visibility table above are for my location in Socorro, New Mexico, however you can generate one for your specific location. The skymap shows the actual path of the ISS in the sky, and what constellations are up at the time of the pass. Since this pass begins about a half-hour after sunset (7:09 PM MDT), we will be in civil twilight; the sky will still be a bit bright, and you can expect to see only a handful the brightest stars and planets shown on this skymap. (For a full explanation of the different kinds of twilight, please see this previous blog post.)
The visibility table lists the time when ISS will rise above the horizon and in what direction around the horizon (azimuth), the time it will be at various altitudes in its pass, and how bright (magnitude) the ISS will appear at those various altitudes. (For a discussion of altitude and azimuth please refer to this previous blog post.)
ISS pass taken with a spherical fisheye lens so you can see the whole of the sky.
This is a good time to cover some astronomy basics. As you see above, the brightness of the ISS is referred to as its magnitude. The stellar magnitude scale is the measure of how bright an object appears to us, with brighter objects having smaller numbers, and fainter objects having larger numbers. For example, the large black dot nearly in the center of this skymap (meaning it would be about directly overhead) is Vega in the constellation Lyra, at a magnitude of 0.03. Move almost straight down from that toward the southern horizon on the map and you’ll see a slightly larger black dot, signifying the planet Jupiter. Right now, Jupiter’s magnitude is about -2.5. A bit to the east of Jupiter is the planet Saturn, currently at about magnitude 1.2 (planet magnitudes obtained from The Sky Live). To list these three objects in order of increasing brightness, we get Saturn being the dimmest at mag 1.2, Vega a bit brighter at mag 0.03, and Jupiter the brightest at mag -2.5.
As you can see from the visibility table, the ISS varies in brightness during its pass, starting dim, reaching its peak brightness of mag -3.4 when it reaches its maximum altitude in the pass, then becoming dimmer again as it nears the opposite horizon. Those of us at dark sky sites may start to see the ISS when it is 10 to 15° above the horizon, while those of you in brighter sky sites may not see it until it gets to a higher altitude.
On this early morning the ISS passed above while I did some light painting below.
One last thing worth pointing out is the cardinal directions shown on the skymap. North and south are where you expect them to be, but east and west are reversed from what you see on a map of the Earth. This is because skymaps are to be held over your head while you look up at them, just as you look up at the sky. Try it and see!
Hopefully I’ve inspired you to take a moment this Friday night to watch the International Space Station pass overhead. Whether you’re in your light polluted backyard or a dark sky site, and it will be your first viewing, your fiftieth (like me), or something in between, I think you will enjoy the view!
M. Colleen Gino, MRO Assistant Director of Outreach and Communications
If you’ve ever been driving in the middle of nowhere right before dawn, you may have noticed a light on the horizon right where the Sun should be rising – only the Sun shouldn’t be rising for another hour or so. Don’t worry, it’s possible that you aren’t losing it! You may have just witnessed false dawn caused by zodiacal light.
Zodiacal light visible to the east before sunrise in the late summer/early fall. The bright streak is the International Space Station.
Zodiacal light is a strange light that shoots up from the eastern horizon right before dawn in the late summer/early autumn and right after Sunset on late winter/early spring nights for those in the northern hemisphere. The triangular shaped phenomenon is caused by light from the Sun that reaches above the horizon while the Sun sits below it, being dispersed by a cloud of interplanetary dust in the plane of our solar system.
This dust is found in a thick cloud – roughly the shape of a pancake – of small particles in our solar system. These particles range in size between about 10 to 300 micrometers. This cloud is called the zodiacal cloud. There are many theories as to its origins, but at least some of it can be attributed to asteroid collision, comet activity, and Kuiper belt collisions. It has long been debated as to just how much of the cloud each of these events may have contributed, and if there exist other event that may also have added their dust to the mix.
Zodiacal light seen to the west just after sunset in the late winter/early spring. Taken at Spaceport America.
Zodiacal light is easiest to see during the period when the ecliptic – the path taken by the Sun and the Moon – is nearly perpendicular to the horizon. It is then that the most amount of light from the Sun can be seen above the horizon, while the Sun is still sitting completely below it. This light reflects off the dust, and isn’t drowned out by the full power of the Sun’s glow.
This light is about the same brightness as the Milky Way, so you’ll need the same amount of darkness to see it as you would the Milky Way. Any light pollution can make it nearly impossible to see. If you’re looking for it, you’ll want to find a place far away from any city light and pick a night close to a new Moon. This month the new Moon occurs on the morning of September 17th, so now is a good time to start looking! And even better, sky gazers in the southern US generally have a better view of Zodiacal light than those living farther north, so if you’re in New Mexico, it may be well worth the attempt! Just get up bright and early – before dawn – find a nice, dark spot, and turn your attention to the east. You may just see it!
M. Colleen Gino, MRO Assistant Director of Outreach and Communications
