NASA's Solar Dynamics Observatory captured these images of a large flare erupting from the sun Feb. 21, 2014. Credit: NASA/SDO
She’s a rainbow! You can see the first moments of a huge flare belching off the sun in the picture above. The so-called X-class flare erupted a few hours ago (at 7:25 p.m. EST Feb. 24, or 12:25 a.m. UTC Feb. 25) and was captured by several spacecraft. If you have a pictures of the sun yourself to share, feel free to post them in the Universe Today Flickr pool.
NASA’s Solar Dynamics Observatory saw the flare growing in at least six different wavelengths of light, which are visible in the image above. This is classified this as an X4.9-class flare, which shows that it is pretty strong. X-flares are the most powerful kind that the sun emits, and each X number is supposed to be twice as intense as the previous one (so an X-2 flare is twice as powerful as X-1, for example).
SpaceWeather.com says this is the most powerful flare of the year so far, emitted from sunspot AR1967 (or more properly speaking, AR1990; sunspots are renamed if they survive a full rotation of the sun, as this one has done twice already!) While solar flares can lead to auroras, in this case it appears the blast was pointed in the wrong direction, the site added.
“Although this flare is impressive, its effects are mitigated by the location of the blast site–near the sun’s southeastern limb, and not facing Earth,” SpaceWeather stated. “Indeed, a bright coronal mass ejection (CME) which raced away from the sun shortly after the flare appears set to miss our planet.”
This image from the Solar and Heliospheric Observatory illustrates increased solar activity between Feb. 18-20, 2014. Credit: ESA/NASA/SOHO/GSFC
The sun goes through an 11-year cycle of sunspot and solar activity, which is supposed to be at its peak right now. This particular peak has been very muted, but lately things have been picking up. The European Space Agency noted that between Feb. 18 and 20, the sun sent out six CMEs in three days, with most of them moving in different directions.
“This level of activity is consistent with what we might expect as the Sun is near its maximum period of activity in the 11-year solar cycle,” ESA stated.
And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.
Occultation of Saturn on Feb. 22, 2014 by Colin Legg
Or, more accurately, watch the Moon pass in front of Saturn. Either way you get the same result: a beautiful video of planetary motion in action!
On the morning of Saturday, Feb. 22, the Moon drifted in front of the planet Saturn from the point of view of certain locations on Earth. Luckily one of those locations was Perth, Australia, where astrophotographer Colin Legg happens to be, and thus we all get to enjoy the fantastic results of his photographic and astronomical acumen.
Check out the video below:
The occultation — as such events are called whenever one celestial object passes in front of, or “hides,” another (the root of the word means “to conceal”) — may make it look like a tiny Saturn is getting absorbed by a giant Moon. But (obviously) they are separated by a vast distance: at the time of the occultation, 9.658 AU, or about 1,444,816,000 kilometers (897.7 million miles).
These sort of events will become a bit more common as the Moon is “headed towards a ‘shallow’ year in 2015 relative to the ecliptic; it will then begin to slowly open back up and ride high around 2025,” according to a recent Universe Today article by David Dickinson.
For those of you interested, Colin lists his equipment as a Celestron C8, f/10, prime focus. His camera is a Canon 5D2, running Magic Lantern RAW video firmware in 3x crop mode @ 1880 x 1056 resolution. Footage was taken at 1/60 sec exposure, ISO 200, 10 fps.
The view of Wednesday's conjunction from selected sites based on four separate continents. Credit: Created by the author using Stellarium.
Are you ready for some lunar versus planetary occultation action? One of the best events for 2014 occurs early this Wednesday morning on February 26th, when the waning crescent Moon — sometimes referred to as a decrescent Moon — meets up with a brilliant Venus in the dawn sky. This will be a showcase event for the ongoing 2014 dawn apparition of Venus that we wrote about recently.
This is one of 16 occultations of a planet by our Moon for 2014, which will hide every naked eye classical planet except Jupiter and only one of two involving Venus this year.
An occultation occurs when one celestial body passes in front of another, obscuring it from our line of sight. The term is used to refer to planets or asteroids blocking out distant stars or the Moon passing in front of stars or planets.
Wednesday’s event has a central conjunction time of 5:00 Universal. Viewers in northwestern Africa based in Mali and southern Algeria and surrounding nations will see the occultation occur in the dawn sky before sunrise, while viewers eastward across the Horn of Africa, the southern Arabian peninsula, India and southeast Asia will see the occultation occur in the daylight.
A comparison of Venus versus the Moon in the daytime taken by Sharin Ahmad (@shahgazer) from Malaysia during the last lunation on January 29th, 2014.
Observers worldwide, including those based in Australia, Europe and the Americas will see a near miss, but early risers will still be rewarded with a brilliant dawn pairing of the second and third brightest objects in the night sky. This will also be a fine time to attempt to spot Venus in the daytime, using the nearby crescent Moon as a guide. It’s easier than you might think! In fact, Venus is actually brighter than the Moon per apparent square arc second of surface area, owing to its higher average reflectivity (known as albedo) of 80% versus the Moon’s dusky 14%.
The International Occultation Timing Association also maintains a chart of ingress and egress times for specific locations along the track of the occultation.
The footprint of the Wednesday occultation of Venus by the Moon. Solid lines indicate where the occultation occurs before sunrise, while the dashed area denotes where the occultation occurs after sunrise. Credit: Created using Occult4.1.0.11.
The Moon occults Venus 21 times in this decade. The last occultation of Venus by the Moon occurred on September 8th, 2013, and the next occurs October 23rd 2014 over the South Pacific in daylight skies very close to the Sun, and is unobservable.
Wednesday’s event also offers a unique opportunity to catch a crescent Venus emerging from behind the dark limb of the Moon. On Wednesday, Venus presents a 34” diameter disk that is 35% illuminated and shining at magnitude -4.3, while the Moon is a 12% illuminated crescent three days from New. Fun fact: February 2014 is missing a New Moon, meaning that both January and March will each contain two!
Apparent path of Venus in relation to the Moon Wednesday morning as seen from a theoretical geocentric (Earth-centered) location. Created using Starry Night Education software.
This also means that a well positioned observer in northwestern Africa would be able to see able to catch the dark limb of Venus creeping out from behind the nighttime side of the Moon against a dark sky. Such favorable occurrences only happen a handful of times per decade, and this week would be a great time to try and briefly spot – or perhaps even video or photograph – a phenomenon know as the ashen light of Venus as the dazzling crescent daytime side of the planet lay obscured by the Moon. Is this effect reported by observers over the years a fanciful illusion, or a real occurrence?
Perhaps, due to the remote location, this chance to spy and record this elusive effect will go unnoticed this time ‘round. The next chance with optimal possibilities to catch a crescent Venus occulted by the Moon against a dark sky occurs next year on October 8th, 2015, favoring the Australian outback. Anyone out there down for an observing expedition to prove or disprove the ashen light of Venus once and for all? Astronomy road trip!
April 22nd, 2009 conjunction of Venus and the Moon as seen from Hudson, Florida. The Photo by author.
This event also provides optimal circumstances as Venus heads towards greatest elongation west of the Sun on March 22nd and the Moon-Venus pair lay 43 degrees west of the Sun during Wednesday’s event. Compare this to the impossible to observe occultation this October, when the pairing is only one degree east of the Sun! The next occultation of Venus for North America occurs next year on December 7th, 2015 and will be visible in the daytime across the extent of the track except for Alaska and Northwestern Canada.
Vexillographers may also want to take note: this week’s Venus-Moon pairing will closely emulate the familiar crescent Moon plus star pairing seen on many national flags worldwide. Did an ancient and unrecorded occultation of Venus by the Moon inspire this meme? Tradition has it that Sultan Alp Arslan settled on the star and crescent for the flag of the Turks after witnessing a close conjunction after the defeat of the Byzantine Army at the Battle of Manzikert on August 26th, 1071 A.D. This tale, however, is almost certainly apocryphal, as no occultations of planets or bright stars by the Moon occurred on or near that date, and only two occultations of Venus by the Moon occurred that year. And Venus was less than two degrees from the Sun on that date, yet another strike against it. In fact, the only occultations of Venus by the Moon in 1071 occurred on June 29th and November 27th. Perhaps Arslan just took a while to decide…
Still, this week’s event provides a great photo-op to have “Fun with Flags” and capture the pair behind your favorite astronomical conjunction-depicting banner. And be sure to send those pics into Universe Today… methinks there’s a good chance of us running a post occultation photo-essay later this week!
M33, the Triangulum Spiral Galaxy, seen here in a 4.3 hour exposure image. Astronomers used JWST to examine a section of its south spiral arm to search out and find nearly 800 newly forming stars. Credit and copyright: John Chumack.
We keep saying this: the universe is more complex than it appears. Conventional thinking in galaxy research postulates that spiral galaxies have star-forming areas, while ellipticals do not due to a lack of gas. While this thinking has been debunked, there’s now emerging research showing a “green valley” of galaxies somewhat in between these two types.
Basically, the research (which includes participation from citizen scientists in the Galaxy Zoo project) is showing that there are two different populations of “green” galaxies, between ellipticals and spirals. Further, what happens to star formation based upon gas in the area.
“In this paper, we take a look at the most crucial event in the life of a galaxy: the end of star formation. We often call this process ‘quenching’ and many astrophysicists have slightly different definitions of quenching. Galaxies are the place where cosmic gas condenses and, if it gets cold and dense enough, turns into stars. The resulting stars are what we really see as traditional optical astronomers,” wrote Kevin Schawinski, a Ph.D. student at the University of Oxford who is on the Galaxy Zoo team, in a blog post.
“Not all stars shine the same way though: stars much more massive than our sun are very bright and shine in a blue light as they are very hot. They’re also very short-lived. Lower mass stars take a more leisurely pace and don’t shine as bright (they’re not as hot). This is why star-forming galaxies are blue, and quiescent galaxies (or ‘quenched’ galaxies) are red: once star formation stops, the bluest stars die first and aren’t replaced with new ones, so they leave behind only the longer-lived red stars for us to observe as the galaxy passively evolves.”
An image of the flash resulting from the impact of a large meteorite on the lunar surface on 11 September 2013, obtained with the MIDAS observatory. Credit: J. Madiedo / MIDAS
Hey, all you astro-photographers/videographers out there: were you shooting the Moon back on September 11, 2013? You may want to review your footage and see if you captured a bright flash which occurred at about 20:07 GMT. Astronomers say a meteorite with the mass of a small car slammed into the Moon at that time and the impact produced a bright flash, and it even would have been easy to spot from the Earth.
According to astronomers Jose M. Madiedo, from the University of Huelva and Jose L. Ortiz, from the Institute of Astrophysics of Andalusia both in Spain, this impact was the longest and brightest confirmed lunar impact flash ever observed, as the “afterglow” of the impact remained visible for 8 seconds.
The astronomers think the bright flash was produced by an impactor of around 400 kg with a width of between 0.6 and 1.4 meters. The rock hit may have hit Mare Nubium at about 61,000 kilometers per hour (38,000 miles per hour) — although the uncertainty of the impact is fairly high, the team says in their paper. But if it is as high as they think, it may have created a new crater with a diameter of around 40 meters. The impact energy was equivalent to an explosion of roughly 15 tons of TNT.
This beats the previous largest impact seen – which occurred just six months earlier in March 2013 – which was estimated to pack as much punch as 5 tons of TNT. Astronomers that explosion was caused by a 40 kg meteoroid measuring 0.3 to 0.4 meters wide, traveling about 90,000 km/hr (56,000 mph.)
How often does an asteroid hit the Moon? Astronomers actually aren’t very sure.
On average, 33 metric tons (73,000 lbs) of meteoroids hit Earth every day, the vast majority of which harmlessly ablates or burns up high in Earth’s atmosphere, never making it to the ground. The Moon, however, has little or no atmosphere, so meteoroids have nothing to stop them from striking the surface.
The lunar impact rate is so uncertain because observations for objects in the mass range of visible impacts from Earth are quite few. But now, astronomers have set up networks of telescopes that can detect them automatically. NASA has the Automated Lunar and Meteor Observatory (ALaMO) at Marshall Space Flight Center, and the Spanish telescopes are part of the Moon Impacts Detection and Analysis System (MIDAS) system.
Lunar meteors hit the ground with so much kinetic energy that they don’t require an oxygen atmosphere to create a visible explosion. The flash of light comes not from combustion but rather from the thermal glow of molten rock and hot vapors at the impact site.
This thermal glow can be detected from Earth as short-duration flashes through telescopes. Generally, these flashes last just a fraction of a second. But the flash detected on September 11, 2013 was much more intense and longer than anything observed before.
Mosaic of zoomed images showing the flash evolution from the Sept. 11, 2013 impact during the first 2 seconds. Time increases from left to right in each row, starting from the upper left. The time interval between two consecutive images in the same row is 0.1 s. Credit: Madiedo, Ortiz, et al. 2014.
“Our telescopes will continue observing the Moon as our meteor cameras monitor the Earth’s atmosphere,” said Madiedo and Ortiz in a press release. “In this way we expect to identify clusters of rocks that could give rise to common impact events on both planetary bodies. We also want to find out where the impacting bodies come from.”
Chelyabinsk fireball recorded by a dashcam from Kamensk-Uralsky north of Chelyabinsk where it was still dawn. A study of the area near this meteor air burst revealed similar signatures to the Tall el_Hammam site.
Looking at the power of the Chelyabinsk meteor (which struck a year ago and is visible starting around 1:15 in the video above) is still terrifying all these months later. Happily for those of on Earth worried about these big space rocks, the world’s space agencies are taking the threat seriously and are starting to implement new tracking systems to look out for more threatening space rocks.
“It was a pretty nasty event. Luckily, no one was killed but it just shows the sort of force that these things have,” said Alan Harris, senior scientist of the DLR Institute of Planetary Research in Berlin, in this new European Space Agency video.
An asteroid that is only about 100 meters (328 feet) in diameter, for example, “could actually completely destroy an urban area in the worst case. So those are the things we’re really looking out for and trying to find ways to tackle.”
Check out the video for some examples of how the Europeans are talking about dealing with this problem, including a fun comparison to cosmic billiards and a more serious discussion on how to shove these rocks aside if they were on a collision course with our planet.
Neil Armstrong and Buzz Aldrin plant the US flag on the Lunar Surface during 1st human moonwalk in history 45 years ago on July 20, 1969 during Apollo 1l mission. Credit: NASA
A big challenge of making history “real” to students is finding a way to make it identifiable. Back in the early days of space exploration, it seemed every launch was on TV and every step to the moon extensively documented on radio, television and other media of the day. In an age where we just pull what we want off of social media and YouTube, the sense of excitement must be hard to convey to younger students.
To bring the inspiration of Apollo 11 to a younger audience, one high school teacher in Maryland took it upon himself to write a play for secondary school students — including much of the original transcript, right down to the “nouns” and “verbs” of the computers the astronauts used.
Richard Zmuda, who teaches in Annapolis, first came up with the idea three years ago after giving a National Honor Society speech to high schoolers where he cited alumni to the students, such as Apollo 11 lunar module pilot Buzz Aldrin.
“I had researched Aldrin for the speech and learned some fascinating details about him personally and about the mission in general,” Zmuda stated. “I realized that, while as a young boy I was able to watch on television Neil Armstrong’s first steps on the moon, none of the students could even remotely share in that experience. Yet it was one of the most important events in the history of mankind.”
Buzz Aldrin’s bootprint on the surface of the moon during the Apollo 11 mission on July 20, 1969. Credit: NASA
The result is a remarkably accurate adaptation of the mission transcript, and one that would be an interesting challenge for young thespians to bring to the stage. There are actual lines of dialog that sound close to what an astronaut of the day would say, such as “Your Co-Elliptic Sequence Initiation Time of Ignition: 125:19:3470.” Teaching the students how to convey a sense of drama, while staying true to the script, would be a fun exercise. It also would require some research so that the students understand what they’re talking about, which is likely the point that Zmuda wanted to convey.
That’s not to say that every line of dialog is that technical. Zmuda works to bring out the drama in several parts of the mission, including how Aldrin initially missed his first test “jump” back on to the lunar ladder and banged his shins against a rung. The staged Aldrin exclaims to the audience, “Well, at least I can say I was the first person to actually PEE on the moon,” something the real person never came close to saying. In a dramatic sense, however — especially given the age of the audience — this was a fun way to show how serious the situation could have been if Aldrin had more trouble getting back up.
Apollo 11 Mission image – Lunar Module at Tranquility Base
Even more interesting is Zmuda’s decision to keep the actors to between four and seven people — three astronauts and either a single person as CapCom in Mission Control, or three people representing the different shifts. This focuses the bulk of the attention on the astronauts, although “Houston” is intended to act as a dramatic foil during the frequent communications blackouts (which did happen in the real mission, too). It also makes it easy for a small drama class to stage the play.
The Apollo 11 adaptation is a fun read for space geeks, and likely is a good tool for teaching history at the high school level and above. Although the script is very technical at times, teaching students how to read this material can be equated to learning how to understand Shakespeare, or to deliver foreign words on stage. It’s a great effort by Zmuda, and hopefully will teach a few students about what the landing represented to space exploration.
The Earth has a single moon, while Saturn has more than 60, with new moons being discovered all the time. But here’s a question, can a moon have a moon? Can that moon’s moon have its own moon? Can it be moons all the way down?
First, consider that we have a completely subjective idea of what a moon is. The Moon orbits the Earth, and the Earth orbits the Sun, and the Sun orbits the center of the Milky Way, which orbits within the Local Group, which is a part of the Virgo Supercluster. The motions of objects in the cosmos act like a set of Russian nesting dolls, with things orbiting things, which orbit other things. So maybe a better question is: could any of the moons in the Solar System have moons of their own? Well actually, one does.
Right now, NASA’s Lunar Reconnaissance Orbiter is happily orbiting around the Moon, photographing the place in high resolution. But humans sent it to the Moon, and just like all the artificial satellites sent there in the past, it’s doomed. No satellite we’ve sent to the Moon has ever orbited for longer than a few years before crashing down into the lunar surface. In theory, you could probably get a satellite to last a few hundred years around the Moon.
But why? How come we can’t make moons for our moon to have a moon of it’s own for all time? It all comes down to gravity and tidal forces. Every object in the Universe is surrounded by an invisible sphere of gravity. Anything within this volume, which astronomers call the “Hill Sphere”, will tend to orbit the object.
So, if you had the Moon out in the middle of space, without any interactions, it could easily have multiple moons orbiting around it. But you get problems when you have these overlapping spheres of influence. The strength of gravity from the Earth tangles with the force of gravity from the Moon.
How many moons are there in the Solar System? Image credit: NASA
Although a spacecraft can orbit the Moon for a while, it’s just not stable. The tidal forces will cause the spacecraft’s orbit to decay until it crashes. But further out in the Solar System, there are tiny asteroids with even tinier moons. This is possible because they’re so far away from the Sun. Bring these asteroids closer to the Sun, and someone’s losing a moon.
The object with the largest Hill Sphere in the Solar System is Neptune. Because it’s so far away from the Sun, and it’s so massive, it can truly influence its environment. You could imagine a massive moon distantly orbiting Neptune, and around that moon, there could be a moon of its own. But this doesn’t appear to be the case.
NASA is considering a mission to capture an asteroid and put it into orbit around the Moon. This would be safer than having it orbit the Earth, but still keep it close enough to extract resources. But without any kind of orbital boost, those tidal forces will eventually crash it onto the Moon. So no, in our Solar System, we don’t know of any moons with moons of their own. In fact, we don’t even have a name for them. What would you suggest?
Hosts: Fraser Cain & Scott Lewis
Astronomers: David Dickinson, Gary Gonella, James McGee, Mike Simmons, Roy Salisbury, Shahrin Ahmad, Tom Nathe
Tonight’s views:
Jupiter with a nice view of the red spot, Venus approaching zenith, Bubble Nebula, the Pleiades, Orion Nebula, Horsehead Nebula, Flame Nebula, Running Man Nebula, the Moon, the Sun, the ISS (photo), the Rosette Nebula, Orion again, M33, Sunspots, Rosette again, California Nebula (multiple views), M81 & M82, Planet “X” (?!?), Andromeda, Flame Nebula again
We hold the Virtual Star Party every Sunday night as a live Google+ Hangout on Air. We begin the show when it gets dark on the West Coast. If you want to get a notification, make sure you circle the Virtual Star Party on Google+. You can watch on our YouTube channel or here on Universe Today.
