Hello, lovelies, and welcome to your favorite roundup of space news: the one corner of current events that doesn’t suck. This week, we’ve got lots of updates from NASA. For one thing, the agency is building a six-mile-wide space telescope. We also found out that an important asteroid is “barely a rubble pile,” and a spacecraft en route to the asteroid might destroy it just by touching it. But the European and Indian space agencies have both had a busy week, too. So has the European Southern Observatory (ESO).
Let’s start at the top.
Betelgeuse Blows Its Stack
Betelgeuse is the bright red star that forms Orion’s right shoulder. The star caught scientists’ attention in late 2019 when it started going dim. It’s been fluctuating in brightness since then, with little clue as to why. But a new analysis of data from Hubble and other observatories may have an answer. Instead of a coronal mass ejection, a team of astrophysicists argues that Betelgeuse experienced a titanic surface mass ejection. Instead of just casting off some spare plasma, the team believes the star actually blew away much of its visible surface.
‘The interior Is Sort of Bouncing’
“We’ve never before seen a huge mass ejection of the surface of a star. We are left with something going on that we don’t completely understand,” said Andrea Dupree, an astrophysicist at the Harvard and Smithsonian Center for Astrophysics in Cambridge, Massachusetts.
It wasn’t a supernova, and the star is still burning. While its outer layer looks normal again, Dupree believes that the star’s internal convection cells are still recovering. Telescope data shows that the surface remains ‘springy.’ “Betelgeuse continues doing some very unusual things right now,” Dupree said. “The interior is sort of bouncing.”
“It’s a totally new phenomenon that we can observe directly and resolve surface details with Hubble,” she added. “We’re watching stellar evolution in real time.”
NASA News
Mostly it’s been quiet from the International Space Station. This week, NASA astronauts on the ISS are planting radish sprouts. (Salad — in spaaaace! I’ll see myself out.) But on the ground, the agency has been busy indeed.
Agency Begins Assembly of Six-Mile-Wide SunRISE Space Telescope
Solar flares and coronal mass ejections (CMEs) can create truly breathtaking auroras around our north and south poles. But their beauty comes with a price. The showiest solar flares are also the biggest. These high-intensity geomagnetic storms can disrupt telecommunications, knock out power, and even destroy satellites in orbit. That’s why NASA is building another space telescope, aptly named SunRISE: to closely study the sun, so we can better understand CMEs and other explosive solar weather. But it’s no ordinary space telescope. (As if a space telescope is ordinary! These modern times.) SunRISE is made of six individual radio telescopes, the first of which just rolled off the production line at the Utah State University Space Dynamics Laboratory in Logan. And by their powers combined, SunRISE will be six miles wide.
SunRISE stands for the Sun Radio Interferometer Space Experiment. Its size might sound like sci-fi, but it’s quite real. Not unlike earthbound interferometers, many telescopes join forces to form one collective super-telescope. The separation between component telescopes becomes the telescope’s effective aperture. For SunRISE, each small satellite, or “SmallSat,” will act as a single radio antenna pointed straight at the sun. The six satellites will orbit Earth in a swarm, tracking solar radio bursts. In addition to mapping the sun itself, NASA hopes to use SunRISE to map the 3D structure of the sun’s magnetic field lines.
Lonely Perseverance Continues to Hunt for Signs of Life on Mars
One of the big Perseverance mission directives is to search for evidence of life on Mars. But Mars has barely any atmosphere. Despite the planet’s “wet era,” when it featured an actual ocean, the Red Planet hasn’t had bio-available water for three and a half billion years. The water evaporated away, just like the planet’s atmosphere, leaving just a whiff of carbon dioxide. That makes it tough to imagine where life could have arisen, let alone how it could have persisted to make detectable fossils.
And it really would need to be fossils in the plural, explained Amy Williams, a participating scientist with NASA’s Perseverance and Curiosity missions.
Extraordinary Claims Require Extraordinary Evidence
Williams said that there are certainly some biosignatures that Perseverance could detect with its onboard instruments. For one, the rover’s cameras could easily photograph the features of macro-scale fossils, like stromatolites (bulbous fossils that come from huge colonies of bacteria).
“However, even with a macroscale texture like that, I think most astrobiologists would require multiple lines of evidence to confirm the biogenicity [the state or property of being biogenic] assessment and refute any abiologic [not associated with or derived from living organisms] origin for the feature,” Williams told Space.
“Sample return is the way to get those multiple lines of evidence,” Williams added, “as we have far greater analytical capabilities in labs here than we’ll be able to send on a rover.”
NASA’s Lawn DART Could Disintegrate Dimorphos
Asteroid impacts may not happen often, but the threat of an extinction-level event is a great motivator. So, NASA decided to lob some practice shots at a few nearby asteroids that pose no threat to the planet. To this end, last year the agency launched its Double Asteroid Redirection Test, or DART. DART will deliberately smash into an asteroid, as part of a simulation of how we might react if a vastly larger space rock was detected on course for Earth.
The target asteroid, Dimorphos, is a moon of the binary asteroid Didymos. At just 170m in diameter, it’s one of the smallest objects we’ve ever tried to target with a spacecraft. In fact, while NASA intended the DART impactor to nudge the moon’s course and excavate into its interior, a new paper from Bern has argued that NASA’s impactor will do much more than that. Instead of just disturbing Dimorphos, DART might disintegrate it.
The argument from researchers at the University of Bern is that asteroids may be far less dense than astronomers previously thought. There is some recent evidence to support this view. OSIRIS-REx’s sampling mission to asteroid Bennu revealed that the asteroid is barely a rubble pile. If Dimorphos has a similar density, it would be like a pile of snowballs. At its expected 24,000 km/h, DART would hit Dimorphos like a mass driver.
According to the researchers, the reason NASA didn’t consider this option is because models assumed a much denser internal structure. But in any case, we won’t have to wait long to find out what happens. NASA currently predicts that DART will reach Didymos on September 26 2022; the ESA will launch a follow-up satellite, Hera, in 2024. Hera should arrive at Didymos by 2027 to evaluate the long-term results of the DART impact.
Today I Learned…
…astronauts have a patch of Velcro inside their helmets, on which to scratch their noses.
Neil Armstrong’s helmet. I guess he preferred the “hook” side? Image courtesy of NASA
Giant Magellan Telescope Scores Further Funding
Speaking of huge telescopes, there’s a new heavyweight contender: the Giant Magellan Telescope. This ground-based telescope will be part of the European Southern Observatory’s Extremely Large Telescope. When it launches, it will have a collecting area of 368 square meters, with a primary mirror more than 25 meters across. The twelve-story telescope will be housed at the ESO’s Las Campanas Observatory, in its aerie in Chile’s Atacama Desert.
The GMT’s enormous size will give it four times the resolving power of the James Webb space telescope — and ten times that of Hubble. “This unprecedented angular resolution, combined with revolutionary spectrographs and high contrast cameras, will work in direct synergy with JWST to empower new scientific discoveries,” the GMT Organization said in a statement.
Image: Giant Magellan Telescope Organization
Six of its seven primary mirrors have already been cast. The telescope is expected to launch in the late 2020s, although we don’t have a firm date. However, this week the GMT nabbed a tidy $207 million in funding, which should help things along.
“We are honored to receive this investment in our future,” said Dr. Robert Shelton, president of the Giant Magellan Telescope Organization. “The funding is truly a collaborative effort from our Founders. It will result in the fabrication of the world’s largest mirrors, the giant telescope mount that holds and aligns them, and a science instrument that will allow us to study the chemical evolution of stars and planets like never before.”
This is just the best game of one-upmanship. What are these people saying to one another? “I see your gigantic, amazing space telescope, and raise you an even more gigantic ground-based telescope?”
TU Delft Makes Tiny Lunar Bugbot
ESA is making a wee bittie lunar robot called Zebro (from zes-benige robot, zes-benige meaning six-legged in Dutch). The adorable bugbot is the size of an A4 notebook, and its builders say it’s so small that it can rideshare on any rocket bound for the moon.
Zebro’s curlicue legs are designed to keep the mini moonbot from getting stuck in debris.
SpaceX Launches 3,000th Starlink Satellite
SpaceX’s Falcon 9 Rocket lifted off from pad 39A Tuesday evening, carrying 52 Starlink satellites. This launch will also mark the 3,000th Starlink satellite in orbit. SpaceX has another Starlink launch from Vandenburg scheduled for this evening, carrying yet another group of satellites into a polar orbit. But the Starlink project itself is experiencing a setback.
FCC Rejects Starlink $886M Grant: ‘Too Risky’
The FCC has denied Starlink’s application for $885.51 million in government funds to build out broadband in underserved or unserved areas. The grant was awarded to the company back in December 2020 under then-FCC chair Ajit Pai. This week, the FCC under Jessica Rosenworcel rejected Starlink’s application on the basis that its application “failed to demonstrate” that the company “could deliver the promised service.” Rosenworcel has made remarks suggesting that the auction was mismanaged. In any event, the FCC has been working to clean up the results for a year.
SpaceX says it can add mobile connectivity to the satellites it already plans to launch.
One of the FCC’s major concerns was the $600 in hardware costs that Starlink customers must pay upfront. The agency also expressed skepticism about whether the company could deliver the full speeds it promised. The FCC did note that Starlink “has real promise,” but right now promises aren’t enough.
India’s First Smallsat Launch Goes Wrong
Unfortunately, not everyone’s satellites got safely into orbit this week. India’s space agency, the Indian Space Research Organization (ISRO) has confirmed reports that the inaugural flight of the country’s Small Satellite Launch Vehicle went fatally awry. It appears that the rocket’s third stage only fired for perhaps a tenth of a second. Nothing exploded, and the satellites did launch, but not into their intended orbits. The satellites were supposed to orbit at an altitude of just over 220 miles. Instead, their orbital altitude is more like 47 miles up.
The ISRO confirmed that the satellites were non-functional, and that they would burn up in the atmosphere within days.
ALMA Astronomers Find an Infant Planet
The James Webb Space Telescope has dominated headlines of late, but it’s not the only record-breaking instrument we’ve got pointed at the heavens. Astronomers announced this week that they’ve found a candidate for the youngest planet we’ve ever observed, using the ALMA (Atacama Large Millimeter/submillimeter Array) radio telescopes. This is also the first time we’ve detected gas in a circumplanetary disk, so chalk up two wins for the authors of the study.
The star system AS 209 is roughly 395 light-years from here, in the constellation Ophiuchus. While observing it, astronomers detected both a circumplanetary disk — the material a planet condenses out of — as well as a Jupiter-sized planet itself. This is an exciting discovery for several reasons. First, the star (and therefore, its planet) are both very young, at ~1.6 million years. Jupiter is thought to have formed within four million years, so a Jupiter-sized gas giant fits some of our planetary models.
AS 209 is a young star in the Ophiuchus constellation that scientists have now determined is host to what may be one of the youngest exoplanets ever. Credit: ALMA (ESO/NAOJ/NRAO), A. Sierra (U. Chile)
But what’s surprising about AS 209, specifically, is how far away its exoplanet is. One AU is the distance from Earth to sun. In our solar system, Jupiter is 5.2 AU away. Our current model for the solar system’s planetary development suggests that Jupiter, Saturn, Uranus, and Neptune all formed closer to the Sun than they are today. At nearly 200 AU from its host star, this planet is forming much farther away from its host star than we would’ve expected.
As we’ve started to learn more about other solar systems, we’ve struggled to find examples that look much like our own. The outer planets are thought to have played pinball in the early days of our Solar System’s formation, but Neptune is roughly 2.7 billion miles away. This planet is 19 billion miles from its own star, but it may have already reached Jupiter’s mass equivalent. If this discovery holds up, it raises some interesting questions about the formation of the solar system and whether or not there might yet be a Planet 9 lurking out beyond Neptune.
Skywatchers Corner
Each summer, Earth passes through the trail of Comet 109P/Swift-Tuttle. Its spiraling trail of debris produces a meteor shower: the Perseids. These night-sky delights are famous for their tendency to produce fireballs: long-tailed streaks of light that arc across the sky in a meteor’s wake. The Perseids go on for weeks — but they peak tonight.
One reason the Perseids are so beloved by skywatchers is that you can even see them under bright city skies. But this year’s shower will also have to contend with the brilliance of the Sturgeon Moon. This is the fourth and final ‘supermoon’ of 2022. Technically, it reached its full stage last night — and I can confirm this, it was bright enough to read by — but the moon will still appear full, well into Saturday.
Saturn: the ‘Lord of the Rings’
If you’re looking for a telescope target that won’t be washed out by the moon, this is a great time to look for Saturn. Right now, Saturn is in opposition. That means it’s on the far side of Earth from the Sun, which means it’s at its brightest. But the planet is also facing the Earth in a way that puts its rings on glorious display. To the naked eye, it will just be a brilliant golden star, but a telescope reveals its astonishing rings.
A map of the night sky, showing Saturn in opposition on August 14th. Image: Starry Night software, via Space.com
Tonight, Saturn will appear above and to the left of the moon, drifting rightward as the night goes on. It takes a few years for Saturn to move between constellations as it tours the sky. But by the spring of 2025, the gas giant will be edge-on, with respect to Earth, making its rings all but invisible.
Now Read:
- Astronomers Spot Dazzling Galactic Collision
- Moonshadow: China Mulls Fleet of Orbital Telescopes
- Webb Telescope Captures Stunning Image of the Cartwheel Galaxy
No comments:
Post a Comment