Sprite with Airglow and Gravity Waves over South Dakota. Credit and copyright: Randy Halverson.
Look! Fast! Sprite lightning occurs only at high altitudes above thunderstorms, only last for a thousandth of a second and emit light in the red portion of the visible spectrum, so they are really difficult to see. But one of our favorite astrophotographers and timelapse artists, Randy Halverson captured sprites during a recent thunderstorm in South Dakota. But wait, there’s more!
In his timelapse video, above, you’ll also see some faint aurora as well as green airglow being rippled by gravity waves.
See some imagery from the storm, below:
More sprites with airglow and gravity waves over South Dakota on August 20, 2014. Credit and copyright: Randy Halverson.
See more images and information about Randy’s fun night of observing these phenomena on his website, dakotalapse.
Noctilucent clouds over Sweden on July 27, 2014. Credit and copyright: Göran Strand
This year, the noctilucent cloud season has been especially eventful, and this new timelapse from Swedish astrophotographer Göran Strand shows these “night-shining” clouds covering the entire sky over the course of 2 hours.
“On the 27th of July 2014 I saw some of the most beautiful Noctilucent Clouds I’ve ever seen,” Göran said via email. “They emerged shortly after sunset and after a while they covered the entire sky.”
In the movie you can see an all-sky timelapse view that shows how these clouds changed during the evening.
See some gorgeous still photos from that night, below:
Noctilucent clouds are wispy, glowing tendrils of high-altitude ice crystals that shine long after the Sun has set. They appear in upper latitudes only and form about 83 km (51 miles) up in the atmosphere. The icy clouds are illuminated by the Sun when it is just below the horizon, giving the clouds their “night-shining” properties.
Also called polar mesospheric clouds, these are the highest cloud formations in the atmosphere. They’ve been associated with rocket launches and space shuttle re-entries, and another theory is that they might also be associated with meteor activity.
Noctilucent clouds over Sweden on July 27, 2014. Credit and copyright: Göran Strand.
"The Chemistry of the Solar System" by Compound Interest's Andy Brunning
Here on Earth we enjoy the nitrogen-oxygen atmosphere we’ve all come to know and love with each of the approximately 24,000 breaths we take each day (not to mention the surprisingly comfortable 14.7 pounds per square inch of pressure it exerts on our bodies every moment.) But every breath we take would be impossible (or at least quickly prove to be deadly) on any of the other planets in our Solar System due to their specific compositions. The infographic above, created by UK chemistry teacher Andy Brunning for his blog Compound Interest, breaks down — graphically, that is; not chemically — the makeup of atmospheres for each of the planets. Very cool!
In addition to the main elements found in each planet’s atmosphere, Andy includes brief notes of some of the conditions present.
“Practically every other planet in our solar system can be considered to have an atmosphere, apart from perhaps the extremely thin, transient atmosphere of Mercury, with the compositions varying from planet to planet. Different conditions on different planets can also give rise to particular effects.”
– Andy Brunning, Compound Interest
And if you’re thinking “hey wait, what about Pluto?” don’t worry — Andy has included a sort of postscript graphic that breaks down Pluto’s on-again, off-again atmosphere as well. See this and more descriptions of the atmospheres of the planets on the Compound Interest blog here.
Ariane 5 launch on Feb. 6, 2013 captured on camera by NASA astronaut Rick Mastracchio
We all know what a big rocket launch looks like from the ground, but this is what it looks like from above the ground — 260 miles above the ground! The photo above was captured from the Space Station earlier today by NASA astronaut Rick Mastracchio, and it shows the contrail from a heavy-lift Ariane 5 that had just launched from ESA’s spaceport on the French Guiana coast: flight VA217, Arianespace’s milestone 250th launch carrying the ABS-2 and Athena-Fidus satellites into orbit.
Rick shared his view on Twitter with his nearly 39,000 followers, and now less than an hour later, we’re sharing it here. (Isn’t technology wonderful?)
For a more “natural” look, here it is reversed:
Rick Mastracchio’s photo of the Ariane 5 launch, rotated 180 degrees.
The ISS was in the process of passing over Costa Rica when the image was taken. The rocket launched from Kourou, French Guiana — about 2,175 miles (3,500 km) away. What a view!
For this and more great images from orbit follow Rick on Twitter @AstroRM.
Watch a video of the VA217 launch below:
The 250th launch performed by Arianespace lifted off from ESA’s spaceport in French Guiana, delivering a dual-satellite payload into geostationary transfer orbit: ABS-2 for global satellite operator ABS, and Athena-Fidus for the defense/homeland security needs of France and Italy. The flight lasted just over 32 minutes. (Source)
Artist's impression of KOI-xxx, fjkdshfkdsajhkfdkfd
Gas planets aren’t always bloated, monstrous worlds the size of Jupiter or Saturn (or larger) they can also apparently be just barely bigger than Earth. This was the discovery announced earlier today during the 223rd meeting of the American Astronomical Society in Washington, DC, when findings regarding the gassy (but surprisingly small) exoplanet KOI-314c were presented.
“This planet might have the same mass as Earth, but it is certainly not Earth-like,” said David Kipping of the Harvard-Smithsonian Center for Astrophysics (CfA), lead author of the discovery. “It proves that there is no clear dividing line between rocky worlds like Earth and fluffier planets like water worlds or gas giants.”
Discovered by the Kepler space telescope — ironically, during a hunt for exomoons — KOI-314c was found transiting a red dwarf star only 200 light-years away — “a stone’s throw by Kepler’s standards,” according to Kipping. (Kepler’s observation depth is about 3000 light-years.)
Relative size comparison of KOI-314c and Earth; both have similar mass. (J. Major)
Kipping used a technique called transit timing variations (TTV) to study two of three exoplanets found orbiting KOI-314. Both are about 60% larger than Earth in diameter but their respective masses are very different. KOI-314b is a dense, rocky world four times the mass of Earth, while KOI-314c’s lighter, Earthlike mass indicates a planet with a thick “puffy” atmosphere… similar to what’s found on Neptune or Uranus.
Unlike those chilly worlds, though, this newfound exoplanet turns up the heat. Orbiting its star every 23 days, temperatures on KOI-314c reach 220ºF (104ºC)… too hot for water to exist in liquid form and thus too hot for life as we know it.
In fact Kipping’s team found KOI-314c to only be 30 percent denser than water, suggesting that it has a “significant atmosphere hundreds of miles thick,” likely composed of hydrogen and helium.
It’s thought that KOI-314c may have originally been a “mini-Neptune” gas planet and has since lost some of its atmosphere, boiled off by the star’s intense radiation.
Not only is KOI-314c the lightest exoplanet to have both its mass and diameter measured but it’s also a testament to the success and sensitivity of the relatively new TTV method, which is particularly useful in multiple-planet systems where the tiniest gravitational wobbles reveal the presence and details of neighboring bodies.
“We are bringing transit timing variations to maturity,” Kipping said. He added during the closing remarks of his presentation at AAS223: “It’s actually recycling the way Neptune was discovered by watching Uranus’ wobbles 150 years ago. I think it’s a method you’ll be hearing more about. We may be able to detect even the first Earth 2.0 Earth-mass/Earth-radius using this technique in the future.”
UV image of Titan acquired by Cassini on April 13 (NASA/JPL-Caltech/SSI)
As high summer slowly but steadily approaches on Saturn, Cassini is opening a window to the seasonal changes that occur not only on the ringed planet but also its moons. Here we can see a dark band developing around Titan’s north polar latitudes, a “fancy collar” made visible in ultraviolet wavelengths.
Polar collars have previously been seen by both Hubble and Voyager 2, and in fact a southern version was observed by HST 5 years after the planet’s 1995 equinox.
This summer collar is thought to be part of a seasonal process, related to the migration of upper-level haze material within Titan’s atmosphere.
Source: CICLOPS (Cassini Imaging Central Laboratory for OPerationS)
Polar mesospheric clouds shine over a midnight sunrise above Alaska on August 4, 2013 (NASA)
Looking for a new desktop background? This might do nicely: a photo of noctilucent “night-shining” clouds seen above a midnight Sun over Alaska, taken from the ISS as it passed over the Aleutian Islands just after midnight local time on Sunday, August 4.
When this photo was taken Space Station was at the “top of the orbit” — 51.6 ºN, the northernmost latitude that it reaches during its travels around the planet.
According to the NASA Earth Observatory site, “some astronauts say these wispy, iridescent clouds are the most beautiful phenomena they see from orbit.” So just what are they? Read on…
Found about 83 km (51 miles) up, noctilucent clouds (also called polar mesospheric clouds, or PMCs) are the highest cloud formations in Earth’s atmosphere. They form when there is just enough water vapor present to freeze into ice crystals. The icy clouds are illuminated by the Sun when it’s just below the horizon, after darkness has fallen or just before sunrise, giving them their eponymous property.
NLCs seen in the southern hemisphere in Jan. 2010 (NASA)
Noctilucent clouds have also been associated with rocket launches, space shuttle re-entries, and meteoroids, due to the added injection of water vapor and upper-atmospheric disturbances associated with each. Also, for some reason this year the clouds appeared a week early.
Some data suggest that these clouds are becoming brighter and appearing at lower latitudes, perhaps as an effect of global warming putting more greenhouse gases like methane into the atmosphere.
“When methane makes its way into the upper atmosphere, it is oxidized by a complex series of reactions to form water vapor,” said James Russell, the principal investigator of NASA’s Aeronomy of Ice in the Mesosphere (AIM) project and a professor at Hampton University. “This extra water vapor is then available to grow ice crystals for NLCs.”
A comparison of noctilucent cloud formation from 2012 and 2013 has been compiled using data from the AIM spacecraft. You can see the sequence here.
And for an incredible motion sequence of noctilucent clouds — taken from down on the ground — check out the time-lapse video below by Maciej Winiarczyk, coincidentally made at around the same time as the ISS photo above:
(The video was featured as the Astronomy Picture of the Day (APOD) for August 19, 2013.)
If you’re like me, you don’t change your computer’s desktop background nearly often enough… especially not considering all the fantastic space images that get released on an almost daily basis. But this picture, shared a couple of weeks ago by NASA’s Marshall Space Flight Center on their Flickr stream, really should inspire you to fix that. (I know it did for me!)
Captured by an Expedition 28 crew member aboard the International Space Station, this beautiful image shows a crescent-lit Moon seen through the upper layers of Earth’s atmosphere.
As it circles the globe, the ISS travels an equivalent distance to the Moon and back in about a day, making an excellent platform for viewing the Earth and its atmosphere. This photo shows the limb of Earth near the bottom transitioning into the orange-colored troposphere, the lowest and most dense portion of the Earth’s atmosphere. The troposphere ends abruptly at the tropopause, which appears in the image as the sharp boundary between the orange- and blue- colored atmosphere. Silvery-blue noctilucent clouds extend far above the Earth’s troposphere.
Expedition 28 began on May 23, 2011, with a crew consisting of Andrey Borisenko, Ron Garan, Alexander Samokutyaev, Sergei Volkov, Mike Fossum, and Satoshi Furukawa.
The season for noctilucent “night-shining” clouds is arriving in the northern hemisphere, when wispy, glowing tendrils of high-altitude ice crystals may be seen around the upper latitudes, shining long after the Sun has set. Found about 83 km (51 miles) up, noctilucent clouds (also called polar mesospheric clouds) are the highest cloud formations in the atmosphere. They’ve been associated with rocket launches and space shuttle re-entries and are now thought to also be associated with meteor activity… and for some reason, this year they showed up a week early.
Noctilucent clouds (NLCs) form between 76 to 85 kilometers (47 to 53 miles) above Earth’s surface when there is just enough water vapor to freeze into ice crystals. The icy clouds are illuminated by the Sun when it is just below the horizon, after darkness has fallen, giving them their night-shining properties. This year NASA’s AIM spacecraft, which is orbiting Earth on a mission to study high-altitude ice, started seeing noctilucent clouds on May 13th.
AIM map of noctilucent clouds over the north pole on June 8 (Credit: LASP/University of Colorado)
“The 2013 season is remarkable because it started in the northern hemisphere a week earlier than any other season that AIM has observed,” reports Cora Randall of the Laboratory for Atmospheric and Space Physics at the University of Colorado. “This is quite possibly earlier than ever before.”
The early start is extra-puzzling because of the solar cycle. Researchers have long known that NLCs tend to peak during solar minimum and bottom-out during solar maximum — a fairly strong anti-correlation. “If anything, we would have expected a later start this year because the solar cycle is near its maximum,” Randall says. “So much for expectations.”
Read more on the NASA AIM page here, and watch the Science@NASA video below for the full story. (Also, check out some very nice NLC photos taken last week in the UK by Stuart Atkinson at Cumbrian Sky.)
Mosaic self-portrait of Curiosity at the John Klein outcrop on Feb. 3, 2013 (NASA/JPL-Caltech/MSSS)
Although today Mars’ atmosphere is sparse and thin — barely 1% the density of Earth’s at sea level — scientists don’t believe that was always the case. The Red Planet likely had a much denser atmosphere similar to ours, long, long ago. So… what happened to it?
NASA’s Curiosity rover has now found strong evidence that Mars lost much of its atmosphere to space — just as many scientists have suspected. The findings were announced today at the EGU 2013 General Assembly in Vienna.
Curiosity’s SAM instrument (NASA/JPL-Caltech)
Curiosity’s microwave oven-sized Sample Analysis at Mars (SAM) instrument analyzed an atmosphere sample last week using a process that concentrates selected gases. The results provided the most precise measurements ever made of isotopes of argon in the Martian atmosphere.
Isotopes are variants of the same element with different atomic weights.
“We found arguably the clearest and most robust signature of atmospheric loss on Mars,” said Sushil Atreya, a SAM co-investigator at the University of Michigan.
SAM found that the Martian atmosphere has about four times as much of a lighter stable isotope (argon-36) compared to a heavier one (argon-38). This ratio is much lower than the Solar System’s original ratio, as estimated from measurements of the Sun and Jupiter.
The argon isotope fractionation provides clear evidence of the loss of atmosphere from Mars. (NASA/JPL)
This also removes previous uncertainty about the ratio in the Martian atmosphere in measurements from NASA’s Viking project in 1976, as well as from small volumes of argon extracted from Martian meteorites retrieved here on Earth.
These findings point to a process that favored loss of the lighter isotope over the heavier one, likely through gas escaping from the top of the atmosphere. This appears to be in line with a previously-suggested process called sputtering, by which atoms are knocked out of the upper atmosphere by energetic particles in the solar wind.
The solar wind may have helped strip Mars of its atmosphere over the course of many hundreds of millions of years (NASA)
Lacking a strong magnetic field, Mars’ atmosphere would have been extremely susceptible to atmospheric erosion by sputtering billions of years ago, when the solar wind was an estimated 300 times the density it is today.
These findings by Curiosity and SAM will undoubtedly support those made by NASA’s upcoming MAVEN mission, which will determine how much of the Martian atmosphere has been lost over time by measuring the current rate of escape to space. Scheduled to launch in November, MAVEN will be the first mission devoted to understanding Mars’ upper atmosphere.
Find out more about MAVEN and how Mars may have lost its atmosphere in the video below, and follow the most recent discoveries of the MSL mission here.
