Screenshot from Thierry Legault's video of three Yaogan satellites flying near the field of view of the Andromeda Galaxy (M31). Credit and copyright: Thierry Legault.
The list of amazing things that astrophotographer Thierry Legault captures with his camera keeps growing! This time, it’s a trio of hard-to see, formation-flying Chinese reconnaissance satellites called Yaogan.
“Yaogan triplets are Chinese reconnaissance satellites flying at 1,100 km in groups of 3, separated by about 100km (5°),” Legault explained to Universe Today.
In this video are two different ‘triplets’ of these satellites taken with Legault’s Sony A7s. First you’ll see the Yoagan 16 A/B/C passing through the sky field that includes M31, the Pleiades, the Hyades, the Orion nebula. Second is Yaogan 20 A/B/C passing over M31 just before disappearing in the shadow of the Earth.
“The magnitude of Yaogans is about 5, barely visible to the naked eye,” Legault said via email. “But sometimes they flare, as you can see in the beginning of the movie.”
The fine tracking Legault did of these objects is incredible, along with the detail of the stars and deep-sky objects. ?
Legault used Calsky – his go-to source for observing – to calculate where he would need to be to see these satellites crossing near the famous deep-sky objects. He drove about 100 km west of his home in Paris to capture this unique video.
According to Robert Christy at zarya.info, the Yaogan satellites are imaging satellites “with a government or military purpose. Some seem to carry optical payloads and others carry radar. There are also some launches into orbits very like the US NOSS satellites.”
Christy lists the tasks of these satellites as imaging for remote sensing for military or government photo-reconnaissance including for “natural resources surveys and, possibly, intelligence gathering. Specific tasks include land survey, crop yield assessment, and input to disaster monitoring and prevention plans.”
There have been 24 launches of these satellites since 2006, with one launching as recently as November 20, 2014. Four of the launches were for “triplets” of these satellites.
Find out more about these satellites at zarya.info.
As always, you can see more of Legault’s find astrophotgraphy at his website. See our review of his newly translated book “Astrophotography” here.
A sketchnote-style infographic created in honor of the EFT-1 test flight for the Orion capsule. Credit and copyright: Gary Schroeder.
For many of us, it’s easier to comprehend complex processes when they are expressed visually. That was the impetus for artist Gary Schroeder in creating this wonderful hand-sketched infographic for NASA’s Exploration Flight Test 1 (EFT-1) for the Orion spacecraft.
“Being very interested in the follow-on program to the Shuttle, I wanted to pay close attention to exactly what was going to happen during the Orion launch from liftoff to splashdown,” Schroeder told Universe Today. “Drawing on my experience in sketchnoting (the practice of taking notes using both words and drawings), I thought an infographic-style sketchnote of EFT-1 would be fun to make. I made one study sketch in the morning based on some quick internet research, let it percolate in my head during the day, and came home after work to render a final version.”
Schroeder created the original artwork in pencil, then scanned it and colorized it in Photoshop.
He uploaded it to Flickr just yesterday and it already has nearly 14,000 views. “It’s been exciting for me to see so much interest in this drawing,” he said.
This just proves that sometimes a little bit of ‘throwback’ goes great with technology!
We’ve talked about the biggest stars, but what about the smallest stars? What’s the smallest star you can see with your own eyes, and how small can they get?
Space and astronomy is always flaunting its size issues. Biggest star, hugest nebula, prettiest most talented massive galaxy, most infinite universe, and which comet came out on top in the bikini category. Blah blah blah.
In an effort to balance the scales a little we’re going look at the other end of the spectrum. Today we’re talking small stars. First, I’m going to get the Gary Coleman and Emmanuel Lewis joke out of the way, so we can start talking about adorable little teeny tiny fusion factories.
We get big stars when we’ve got many times the mass of the Sun’s worth of hydrogen in one spot. Unsurprisingly, to get smaller stars we’ll need less hydrogen, but there’s a line we can’t cross where there’s so little, that it won’t generate the temperature and pressure at its core to ignite solar fusion. Then it’s a blob, it’s a mess. It’s clean-up in aisle Andromeda. It’s who didn’t put the lid back on the jar marked H.
So how small can stars get? And what’s the smallest star we know about? In the traditional sense, a star is an object that has enough mass and pressure in its core that it can ignite fusion, crushing atoms of hydrogen into helium.
Fusion is exothermic, releasing energy. It’s this energy that counteracts the force of gravity pulling everything inward. That gives you the size of the star and keeps it from collapsing in on itself.
By some random coincidence and fluke of nature our Sun is exactly 1 solar mass. Actually, that’s not true at all, our shame is that we use our Sun as the measuring stick for other stars. This might be the root of this size business. We’re in an endless star measuring contest, with whose is the most massive and whose has the largest circumference?
So, as it turns out, you can still have fusion reactions within a star if you get all the way down to 7.5% of a solar mass. This is the version you know as a red dwarf. We haven’t had a chance to measure many red dwarf stars, but the nearest star, Proxima Centauri, has about 12.3% the mass of the Sun and measures only 200,000 kilometers across. In other words, the smallest possible red dwarf would only be about 50% larger than Jupiter.
There is an important distinction, this red dwarf star would have about EIGHTY times the mass of Jupiter. I know that sounds crazy, but when you pile on more hydrogen, it doesn’t make the star that much bigger. It only makes it denser as the gravity pulls the star together more and more.
At the time I’m recording this video, this is smallest known star at 9% the mass of the Sun, just a smidge over the smallest theoretical size.
X-Ray image of Proxima Centauri. Image credit: Chandra
Proxima Centauri is about 12% of a solar mass, and the closest star to Earth, after the Sun. But it’s much too dim to be seen without a telescope. In fact, no red dwarfs are visible with the unaided eye. The smallest star you can see is 61 Cygni, a binary pair with one star getting only 66% the size of the Sun. It’s only 11.4 light years away, and you can just barely see it in dark skies. After that it’s Spock’s home, Epsilon Eridani, with 74% the size of the Sun, then Alpha Centauri B with 87%, and then the Sun. So, here’s your new nerd party fact. The Sun is the 4th smallest star you can see with your own eyes. All the other stars you can see are much bigger than the Sun. They’re all gigantic terrifying monsters.
And in the end, our Sun is absolutely huge compared to the smallest stars out there. We here like to think of our Sun as perfectly adequate for our needs, it’s ours and all life on Earth is there because of it. It’s exactly the right size for us. So don’t you worry for one second about all those other big stars out there.
And if you like what you see, come check out our Patreon page and find out how you can get these videos early while helping us bring you more great content!
Dr. Neil deGrasse Tyson contemplates the Big Bang. Image courtesy of Fox.
This spring, space fans had a virtual campfire to flock to: the new Cosmos series, which aired on Fox and National Geographic for 13 science-filled episodes.
The series attracted at least three million viewers a week, generated discussions (positive and negative) on social media, brought host Neil deGrasse Tyson to even higher heights of fame, and once again, showed the general public how neat space is.
Well, guess what. According to producer Seth MacFarlane, Cosmos could come back for a second run — which would supercede the predecessor series from the 1980s, narrated by Carl Sagan!
“Early, preliminary discussions for a 2nd season of #Cosmos– If you want to see more of the great @neiltyson, tweet him your love!” MacFarlane wrote on Twitter yesterday (Dec. 3).
His comments follow a posting on Reddit that surfaced in a couple of news reports yesterday, one from a reported viewer of a deGrasse Tyson talk in New York City:
“I just attended a presentation by Tyson at NJPAC in Newark, NJ,” the posting read. “During the Q&A portion, he told the audience that he’s meeting with producers tomorrow in NYC to discuss the next “season” (for lack of better term) of COSMOS. He didn’t go into further detail, but thought this was interesting since up until this point the updated show was just considered a one-off series (ie 13 episodes).”
We say it every year, but Steve Cariddi’s wonderful Year in Space Wall Calendar is the perfect holiday gift! It’s full of amazing color images, daily space facts, historical references, and it even shows you where you can look in the sky for all the best astronomical sights.
The 2015 edition is now available to order, and thanks to Steve, Universe Today has 5 copies to give away!
This is a gorgeous wall calendar that has over 120 beautiful photos of space, and is larger, more lavishly illustrated, and packed with more information than any other space-themed wall calendar. It’s a huge 16 in. x 22 in. when hanging up!
Other features of this calendar:
– Background info and fun facts
– A sky summary of where to find naked-eye planets
– Space history dates
– Major holidays (U.S. and Canada)
– Daily Moon phases
– A mini-biography of famous astronomer, scientist, or astronaut each month.
To be entered into our giveaway drawing, just put your email address into the box at the bottom of this article (where it says “Enter the Giveaway”) before Tuesday, December 9, 2014.
If this is the first time you’re registering for a giveaway from Universe Today, you’ll receive a confirmation email immediately where you’ll need to click a link to be entered into the drawing. For those who have registered previously, you’ll receive an email later where you can enter this drawing.
These calendars normally sell for $17.95, but Universe Today readers can buy the calendar for only $13.95 or less (using the “Internet” discount), and get free U.S. shipping and discounted international shipping. There are also volume discounts. Check out all the details here.
It’s published in cooperation with The Planetary Society, with an introduction by Bill Nye. Our thanks to Steve Cariddi for providing this giveaway opportunity for our readers!
Artist depiction of Huygens landing on Titan. Credit: ESA
It’s almost exactly 10 years ago that humanity parachuted a spacecraft into Titan, that moon of Saturn that could hold chemistry similar to what sat on Earth before life arose. Called Huygens, the probe survived for just about an hour on the surface on Jan. 14, 2005, transmitting information back about conditions there and on the way down.
Huygens is long dead, but its carrier craft is doing just fine. On Dec. 10, Cassini will make the 107th close pass by Titan to learn more about the moon’s atmosphere. Although Huygens made it to the surface fine, showing at least a basic understanding of how a parachute behaves on Titan, there’s still so much more we need to learn.
Specifically, Cassini’s different instruments have been coming up with different answers for Titan’s atmospheric density, so this flyby is hoping to resolve some of that. In part, they hope to get more accurate measurements by measuring how much drag the spacecraft experiences when it flies past the moon.
Titan’s landscape as seen by the Huygens probe descent through Saturn’s largest moons atmosphere (credit: ESA, NASA, JPL, UA, Rene Pascal)
When Huygens probed the atmosphere on its way down, scientists figured that its measurements agreed in many ways with those taken by the flying-by Voyager 2 spacecraft previously. That said, the probe also discovered “a significant correspondence of wind shear and buoyant stability structures” in the stratosphere and lower tropopause of Titan, according to a 2006 presentation on Huygens results.
Earth's Hadean Eon is a bit of a mystery to us, because geologic evidence from that time is scarce. Researchers at the Australian National University have used tiny zircon grains to get a better picture of early Earth. Credit: NASA
During the Hadean Eon, some 4.5 billion years ago, the world was a much different place than it is today. As the name Hades would suggest (Greek for “underworld”), it was a hellish period for Earth, marked by intense volcanism and intense meteoric impacts. It was also during this time that outgassing and volcanic activity produced the primordial atmosphere composed of carbon dioxide, hydrogen and water vapor.
Little of this primordial atmosphere remains, and geothermal evidence suggests that the Earth’s atmosphere may have been completely obliterated at least twice since its formation more than 4 billion years ago. Until recently, scientists were uncertain as to what could have caused this loss.
But a new study from MIT, Hebrew Univeristy, and Caltech indicates that the intense bombardment of meteorites in this period may have been responsible.
This meteoric bombardment would have taken place at around the same time that the Moon was formed. The intense bombardment of space rocks would have kicked up clouds of gas with enough force to permanent eject the atmosphere into space. Such impacts may have also blasted other planets, and even peeled away the atmospheres of Venus and Mars.
In fact, the researchers found that small planetesimals may be much more effective than large impactors – such as Theia, whose collision with Earth is believed to have formed the Moon – in driving atmospheric loss. Based on their calculations, it would take a giant impact to disperse most of the atmosphere; but taken together, many small impacts would have the same effect.
Artist’s concept of a collision between proto-Earth and Theia, believed to happened 4.5 billion years ago. Credit: NASA
Hilke Schlichting, an assistant professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences, says understanding the drivers of Earth’s ancient atmosphere may help scientists to identify the early planetary conditions that encouraged life to form.
“[This finding] sets a very different initial condition for what the early Earth’s atmosphere was most likely like,” Schlichting says. “It gives us a new starting point for trying to understand what was the composition of the atmosphere, and what were the conditions for developing life.”
What’s more, the group examined how much atmosphere was retained and lost following impacts with giant, Mars-sized and larger bodies and with smaller impactors measuring 25 kilometers or less.
What they found was that a collision with an impactor as massive as Mars would have the necessary effect of generating a massive a shockwave through the Earth’s interior and potentially ejecting a significant fraction of the planet’s atmosphere.
However, the researchers determined that such an impact was not likely to have occurred, since it would have turned Earth’s interior into a homogenous slurry. Given the appearance of diverse elements observed within the Earth’s interior, such an event does not appear to have happened in the past.
A series of smaller impactors, by contrast, would generate an explosion of sorts, releasing a plume of debris and gas. The largest of these impactors would be forceful enough to eject all gas from the atmosphere immediately above the impact zone. Only a fraction of this atmosphere would be lost following smaller impacts, but the team estimates that tens of thousands of small impactors could have pulled it off.
Artist’s concept of the early Earth, showing a surface pummeled by large impacts. Credit: Simone Marchi
Such a scenario did likely occur 4.5 billion years ago during the Hadean Eon. This period was one of galactic chaos, as hundreds of thousands of space rocks whirled around the solar system and many are believed to have collided with Earth.
“For sure, we did have all these smaller impactors back then,” Schlichting says. “One small impact cannot get rid of most of the atmosphere, but collectively, they’re much more efficient than giant impacts, and could easily eject all the Earth’s atmosphere.”
However, Schlichting and her team realized that the sum effect of small impacts may be too efficient at driving atmospheric loss. Other scientists have measured the atmospheric composition of Earth compared with Venus and Mars; and compared to Venus, Earth’s noble gases have been depleted 100-fold. If these planets had been exposed to the same blitz of small impactors in their early history, then Venus would have no atmosphere today.
She and her colleagues went back over the small-impactor scenario to try and account for this difference in planetary atmospheres. Based on further calculations, the team identified an interesting effect: Once half a planet’s atmosphere has been lost, it becomes much easier for small impactors to eject the rest of the gas.
The researchers calculated that Venus’ atmosphere would only have to start out slightly more massive than Earth’s in order for small impactors to erode the first half of the Earth’s atmosphere, while keeping Venus’ intact. From that point, Schlichting describes the phenomenon as a “runaway process — once you manage to get rid of the first half, the second half is even easier.”
This gave rise to another important question: What eventually replaced Earth’s atmosphere? Upon further calculations, Schlichting and her team found the same impactors that ejected gas also may have introduced new gases, or volatiles.
“When an impact happens, it melts the planetesimal, and its volatiles can go into the atmosphere,” Schlichting says. “They not only can deplete, but replenish part of the atmosphere.”
The “impact farm:, an area on Venus marked by impact craters and volcanic activity. Credit: NASA/JPL
The group calculated the amount of volatiles that may be released by a rock of a given composition and mass, and found that a significant portion of the atmosphere may have been replenished by the impact of tens of thousands of space rocks.
“Our numbers are realistic, given what we know about the volatile content of the different rocks we have,” Schlichting notes.
Jay Melosh, a professor of earth, atmospheric, and planetary sciences at Purdue University, says Schlichting’s conclusion is a surprising one, as most scientists have assumed the Earth’s atmosphere was obliterated by a single, giant impact. Other theories, he says, invoke a strong flux of ultraviolet radiation from the sun, as well as an “unusually active solar wind.”
“How the Earth lost its primordial atmosphere has been a longstanding problem, and this paper goes a long way toward solving this enigma,” says Melosh, who did not contribute to the research. “Life got started on Earth about this time, and so answering the question about how the atmosphere was lost tells us about what might have kicked off the origin of life.”
Going forward, Schlichting hopes to examine more closely the conditions underlying Earth’s early formation, including the interplay between the release of volatiles from small impactors and from Earth’s ancient magma ocean.
“We want to connect these geophysical processes to determine what was the most likely composition of the atmosphere at time zero, when the Earth just formed, and hopefully identify conditions for the evolution of life,” Schlichting says.
Schlichting and her colleagues have published their results in the February edition of the journal Icarus.
Artist’s impression of the deep blue planet HD 189733b, based on observations from the Hubble Space Telescope. Credit: NASA/ESA.
If you think exoplanet detections are only in the realm of professional planet-hunting telescopes such as Kepler, take a look at the video above. David Schneider, a senior editor for IEEE Spectrum, explains that it takes little more than a DSLR camera and a camera lens to catch a glimpse.
Schneider told Universe Today that he’s not an experienced amateur observer, nor should his equipment be expected to detect new exoplanets. But the potential for the future is interesting, he explained.
“I was simply trying to detect the signature of a known exoplanet, one that was discovered years ago with far more sophisticated gear,” he wrote in an e-mail. “I knew exactly which star to look at, when the transit occurs, and what the change in brightness would be. I relied on the expertise of professional astronomers to provide all that information.”
Here’s the setup: a Canon EOS Rebel XS DSLR, a 300-millimeter Nikon telephoto lens, an adapter to get the Nikon talking to the Canon, and a self-built “barn door tracker” that he constructed based on descriptions he found on the web. (His IEEE Spectrum article has more details.)
Schneider chose HD 189733, whose hostile-to-life “deep blue” exoplanet is about 63 light-years away and transits the face of the star every 2.2 days. But often these transits take place at inconvenient times (such as during the day, and the star is low on the horizon). He also faced several cloudy nights, meaning it was several weeks until he could take the imagery.
Once that was finished, Schneider ran the pictures through a piece of astronomical imaging software called Iris. In Schneider’s words, this is how the software helped him pick out the planet:
At the most basic level, Iris allows you to perform the corrections that are customary for really all types of digital astrophotography. In particular, you correct for ‘hot pixels’ in your camera sensor and for variations in the sensitivity of the sensor across the frame. This is standard stuff in astrophotography, requiring that you take images with the lens cap on (so-called “darks”), of a uniformly illuminated background (“flats”), and so forth.
For this project, you also need to use the tools that Iris provides to do what’s called aperture photometry. In a nutshell, you have to adjust the registration of the set of images you collect so that the stars are in the same position in each image. Then you have to set up things in Iris to do photometric measurements of a selected set of stars in one frame. After that, Iris will perform the photometry you want on the whole set of images you have in an automated fashion.
While his equipment isn’t sophisticated enough to account for “false positives” such as a sunspot going across a star — amateurs are more at the stage of confirming professional observations — Schneider pointed out there are many similar projects to his own. Among them are KELT-NORTH (which inspired his search), Evryscope, and this group at the University of Arizona.
“My project merely highlights that you can get your feet wet in this area with some really cheap hardware,” Schneider said. He recommends those that want to do similar work to his read the IEEE Spectrum article, buy the hardware required, read up on astrophotography and Iris, and not be afraid to experiment.
Schneider added he wasn’t trying to do “anything special” — many amateurs have encountered similar success — but he had a lot of fun. “Maybe because I’m a bit of a computer nerd, I found digital astrophotography to be a lot more enjoyable than actually looking through a telescope, which in the few times I’ve done that often involved a lot of squinting and unpleasant vibration.”
NASA’s first Orion spacecraft atop Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida one day prior to launch set for Dec. 4, 2014. Credit: Ken Kremer - kenkremer.com
Wind gusts, an issue with valves on the Delta IV Heavy rocket, and an errant cruise ship all contributed to scrub the scheduled maiden test fight of NASA’s Orion spacecraft.
The launch team has tentatively rescheduled a new liftoff time of 7:05 a.m. EST on Friday, December 5 as the opening of a 2-hour, 39 minute window. Launch coverage will begin at 6 a.m. EST tomorrow on NASA TV. However, forecasts call for just 40% chance of acceptable weather conditions on Friday.
The test flight was scheduled from Launch Complex 37 at Cape Canaveral Air Force Station for a four-and-a-half-hour test flight of an uncrewed Orion spacecraft to Earth orbit. The countdown was halted twice when wind gusts exceeded limits. The countdown was also delayed when a boat entered restricted waters off the coast near the Launchpad.
Then, during a third launch attempt an issue with propellant valves on the Delta 4 Heavy’s first stage could not be resolved before the launch window closed.
The planned two-orbit Exploration Flight Test 1 (EFT-1) flight around Earth will lift the Orion spacecraft and it’s attached second stage to an orbital altitude of 3,600 miles, about 15 times higher than the International Space Station (ISS) – and farther than any human spacecraft has journeyed in 40 years. It will test several key systems on Orion, including electronics, the heat shield and parachutes.
Universe Today’s Ken Kremer is on hand in Florida and will provide continuing coverage of the test flight. You can also follow NASA’s Orion Blog for updates.
NASA’s first Orion spacecraft and Delta 4 Heavy Booster unveiled at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida prior to launch set for Dec. 4, 2014. Credit: Ken Kremer - kenkremer.com
KENNEDY SPACE CENTER, FL – The inaugural blastoff of NASA’s new Orion capsule is now just hours away.
We are counting down to NASA’s new generation of human spaceflight vehicles that starts humanity on the road to Mars.
Update: Technical issue delay 1st Orion launch. Details to follow.
“This is a big deal and its importance cannot be underestimated,” NASA Administrator Charles Bolden told the media during a briefing at the Delta pad.
NASA’s first Orion spacecraft and Delta 4 Heavy Booster unveiled at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida prior to launch set for Dec. 4, 2014. Credit: Ken Kremer – kenkremer.com
Just eight hours before the planned liftoff, the media, including myself, witnessed the rollback of the service tower to unveil Orion and its Delta IV Heavy booster rocket to the heavens where it soon soar on it first test flight.
Enjoy my photo gallery herein.
The Orion capsule is designed to carry astronauts farther into space than ever before and open a new era in human spaceflight.
Orion is slated to lift off on a United Launch Alliance Delta IV Heavy rocket on its inaugural test flight to space on the uncrewed Exploration Flight Test-1 (EFT-1) mission at 7:05 a.m. EST on December 4, 2014, from Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.
The launch window extends for 2 hours and 39 minutes.
