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Space: From asteroid collisions and moon journeys to stunning telescope images

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For decades, the faintest hint of cosmic pessimism has been limiting expectations if not dreams. Now, we’re in the midst of a new space race

In September this year, more than 10 million kilometres out in space, a little spaceship collided with a large asteroid called Dimorphos.

This was on purpose, a good shot. The mission was to disrupt the orbital path Dimorphos takes around its paired larger asteroid Didymos, which it did, by a lot more even than NASA expected

Neither asteroid was headed for Earth. But if one ever happens to, a solution is now clear. We don’t need to blow it up like Bruce Willis in Armageddon. We’ll just nudge it away. The Double Asteroid Redirection Test (DART) was a striking “proof of concept” experiment, and not even the biggest space story of the year, although NASA administrator Bill Nelson called it “a watershed moment for planetary defence, and a watershed moment for humanity.”

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At the end of 2022, things are looking up, space-wise. Just a few weeks before NASA hit that asteroid bullseye, the first images arrived back on Earth from the new James Webb Space Telescope, stationed out at a stable place in the interplay between Sun and Earth gravity, facing out into the receding darkness. This successor to the 32-year-old Hubble launched last Christmas Day, equipped with, among other fancy things, a Canadian made device called the Near Infrared Imager and Slitless Spectrograph (NIRISS). Already, it is revealing new insights about how the universe’s first galaxies formed out of the remnants of the Big Bang.

Then in November, the Artemis 1 mission set off around the Moon and back on a new spaceship called Orion, carrying humanoid technical mannequins to prove it can one day safely carry human crew, and a new thermal shield to protect them from re-entry temperatures higher than anything previously encountered in crewed spaceflight.

Space news barely took a day off this year. Two days after Orion splashed down in the Pacific Ocean on Dec. 11, a research paper was published about a chance encounter on Mars, in which a huge dust devil, more than 100 metres tall, 25 metres across, and moving about 18 km/h across the surface of Mars happened to run directly over the Perseverance rover, which captured audio as well as video, and beamed it back to Earth.

This whisper of extraterrestrial wind and its detailed acoustic analysis was no major breakthrough, just a minor scientific curiosity by itself, but considered alongside the other major space advancements of 2022, it seemed to herald more wondrous curiosities to come.

Next year, for example, the European Space Agency plans to launch the JUICE mission (Jupiter Icy Moons Explorer) to map the icy moons Ganymede, Callisto and Europa that orbit the solar system’s largest planet. NASA plans both to launch a mission to an asteroid, and to welcome the return of samples from another asteroid, from a mission launched in 2020.

Even the grandest plans and predictions are coming into focus, thanks especially to Artemis, after a couple of initial hiccups delayed the launch. Its explicit goal is eventually to put an outpost space station in lunar polar orbit before sending a crewed mission to the surface and back. An entire generation of space scientists is invested in what would follow, a crewed Mars mission, and the beginning of interplanetary colonization.

Telescopes likewise are opening new horizons, penetrating further back into space and time, in some cases almost as far as possible, according to known physics, back even to light produced at the universe’s creation that has been travelling ever since, stretched into infrared by the expansion of the universe itself. The new James Webb Space Telescope can detect this light 100 times fainter than Hubble.

What its research team can see in the resulting images, as the University of Toronto astronomer Lamiya Mowla puts it, “is not a picture of a point in time. This is a history of the universe.”

It is heady and exciting stuff. Taken together, all this evidence suggests the future of space science and exploration looks a bit more today like it did a generation ago, like an accelerating golden age.

Space is back. It is a subtle shift in our shared cultural outlook to the cosmos, but it’s there. For decades, the faintest hint of cosmic pessimism has been limiting expectations if not dreams.

Maybe there is no grand unified theory to be found in physics, no quantum theory of gravity. Maybe getting to Mars is practically impossible. Maybe life really is a unique fluke. The end of the Space Shuttle program a decade ago threatened to doom the International Space Station, which once promised to be a stepping stone for humans to the cosmos, not the dead-end “tin can” of Space Oddity. Maybe the momentum had left the space project.

The mid-century superpower space race is not only over, but at least one racer has degenerated into an imperial basket case, failing this year at even earthbound conquest. The Russian Soyuz spacecraft remains the workhorse of human transit to the space station, and until recently it was the only way to get there, but this month’s coolant leak was a reminder that it is 20th century technology for a 20th century purpose.

Now there are more space racers than ever before. They include China, of course, and Japan, also India, which will launch Chandrayaan 3 early next year, trying to land a rover on the Moon, and redeem the software glitch that crashed Chandrayaan 2’s landing in 2019.

Private industry has picked up slack in rocketry. SpaceX has proved the benefit of re-usable rockets in launching at a fraction of what NASA spends to launch its new Space Launch System, and plans to soon test its Starship craft, designed for crewed flight both in orbit and eventually to Mars.

Technology has offered up not just new telescopes in space with vastly increased resolution, but also revolutionary new ways of looking, such as gravitational wave astronomy.

In an interview, Mowla reflected on the scientific excitement of the new space telescope. She is an observational astronomer studying the structural evolution of massive galaxies in the early universe with images from both Hubble and Webb, and her work illustrates this renewed sense of promise in space science.

Hubble was launched in the era of floppy disks, before cell phones, with very low memory. “Now we can fit so much data on these chips,” she said. “There is definitely a technological explosion that happened between Hubble and JWST.”

She and colleagues working with new data from Webb recently discovered a galaxy nicknamed The Sparkler, which is interesting because it is both very distant and very old. It was already old when the light detected by Webb started its journey 9 billion years ago.

“So it must be very old,” she said. This was a basic goal of Webb, to see the very first galaxies, composed of the very first stars, and to learn how they first formed, and why today some are ultra diffuse, “like ghosts,” almost transparent, while others are compact and bright.

The Sparkler is good evidence that a lot of the structural formation is happening very early on, Mowla said.

In space, you can only see what used to be, not what presently is. Light moves so fast that it fools us in our everyday lives. We act as if it doesn’t matter, but there’s always a gap, the time it takes light to travel at its constant speed of about a billion kilometres an hour. Light is like the future. You can never truly see it coming. But it gets here quick.

“It’s one of the best parts of living in this universe, that every time you look up in the sky you’re essentially time travelling,” Mowla said. “We can never know what the sun looks like right at this moment, we have to wait 8 minutes to find out.”

It is the same for other stars, only more so, each one a different time away into the past.

“You’re looking at so many points in time at the same time. It gives you shivers, right?” she said.

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Asteroid 2023 BU just passed a few thousand kilometres from Earth. Here’s why that’s exciting – The Tribune India

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Perth (Australia), January 28

There are hundreds of millions of asteroids in our Solar System, which means new asteroids are discovered quite frequently. It also means close encounters between asteroids and Earth are fairly common.

Some of these close encounters end up with the asteroid impacting Earth, occasionally with severe consequences.

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A recently discovered asteroid, named 2023 BU, has made the news because today it passed very close to Earth.

Discovered on January 21 by amateur astronomer Gennadiy Borisov in Crimea, 2023 BU passed only about 3,600 km from the surface of Earth (near the southern tip of South America) six days later on January 27.

That distance is just slightly farther than the distance between Perth and Sydney and is only about 1 per cent the distance between Earth and our Moon.

The asteroid also passed through the region of space that contains a significant proportion of the human-made satellites orbiting Earth.

All this makes 2023 BU the fourth-closest known asteroid encounter with Earth, ignoring those that have impacted the planet or our atmosphere.

How does 2023 BU rate as an asteroid and a threat?

2023 BU is unremarkable, other than that it passed so close to Earth. The diameter of the asteroid is estimated to be just 4–8 metres, which is on the small end of the range of asteroid sizes.

There are likely hundreds of millions of such objects in our Solar System, and it is possible 2023 BU has come close to Earth many times before over the millennia. Until now, we have been oblivious to the fact.

In context, on average a 4-metre-diameter asteroid will impact Earth every year and an 8-metre-diameter asteroid every five years or so                  

Asteroids of this size pose little risk to life on Earth when they hit because they largely break up in the atmosphere. They produce spectacular fireballs, and some of the asteroids may make it to the ground as meteorites.

Now that 2023 BU has been discovered, its orbit around the Sun can be estimated and future visits to Earth predicted. It is estimated there is a 1 in 10,000 chance  2023 BU will impact Earth sometime between 2077 and 2123.

So, we have little to fear from 2023 BU or any of the many millions of similar objects in the Solar System.

Asteroids need to be greater than 25 metres in diameter to pose any significant risk to life in a collision with Earth; to challenge the existence of civilisation, they’d need to be at least a kilometre in diameter.

It is estimated there are fewer than 1,000 such asteroids in the Solar System and could impact Earth every 5,00,000 years. We know about more than 95 per cent of these objects.

Will there be more close asteroid passes?

2023 BU was the fourth closest pass by an asteroid ever recorded. The three closer passes were by very small asteroids discovered in 2020 and 2021 (2021 UA, 2020 QG and 2020 VT).

Asteroid 2023 BU and countless other asteroids have passed very close to Earth during the nearly five billion years of the Solar System’s existence, and this situation will continue into the future.

What has changed in recent years is our ability to detect asteroids of this size, such that any threats can be characterised. That an object roughly five metres in size can be detected many thousands of kilometres away by a very dedicated amateur astronomer shows that the technology for making significant astronomical discoveries is within reach of the general public. This is very exciting.

Amateurs and professionals can together continue to discover and categorise objects, so threat analyses can be done. Another very exciting recent development came last year, by the Double Asteroid Redirection Test (DART) mission, which successfully collided a spacecraft into an asteroid and changed its direction.

DART makes plausible the concept of redirecting an asteroid away from a collision course with Earth if a threat analysis identifies a serious risk with enough warning. (The Conversation)

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An SUV-sized asteroid zoom by Earth in close shave flyby in this time-lapse video

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Asteroid 2023 BU zipped past Earth Thursday night (Jan. 26) to the delight of amateur astronomers worldwide. For skywatchers without access to a telescope or those who had their view hampered by bad weather, luckily the Italy-based Virtual Telescope Project was there to observe the event and livestream the whole thing for free.

The Virtual Telescope is a robotic telescope operated by Italian amateur astronomer Gianluca Masi near Rome, Italy. As 2023 BU hurtled toward Earth, the telescope was able to track the rock through a gap in the clouds when it was about 13,670 miles (22,000 kilometers) from the closest point on Earth’s surface (about the altitude of the GPS navigation satellite constellation) and 22,990 miles (37,000 km) from the Virtual Telescope.

Masi, who shared an hour-long webcast of the observations on the Virtual Telescope website, wasn’t able to capture the closest approach as clouds rolled in, however. Nonetheless, the Virtual Telescope Project was able to get a good look at the car-sized rock, seen in time-lapse above.

 

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The Italy-based Virtual Telescope captured asteroid 2023 BU shortly before its closest approach to Earth. (Image credit: The Virtual Telescope Project)

The rock, discovered less than a week ago on Saturday (Jan. 21), passed above the southern tip of South America at 7:27 p.m. EST on Thursday Jan. 26 (0027 GMT on Jan. 27), at a distance of only 2,240 miles (3,600 km) at its closest point to Earth’s surface.

This close approach makes 2023 BU the fourth nearest asteroid ever observed from Earth, with the exception of five space rocks that were detected before diving into Earth’s atmosphere.

Only 11.5 to 28 feet wide (3.5 to 8.5 meters), 2023 BU posed no danger to the planet. If the trajectories of the two bodies had intersected, the asteroid would mostly have burned up in the atmosphere with only small fragments possibly falling to the ground as meteorites.

In the videos and images shared by Masi, the asteroid is seen as a small bright dot in the center of the frame, while the longer, brighter lines are the surrounding stars. In reality, of course, it was the asteroid that was moving with respect to Earth, traveling at a speed of 21,000 mph (33,800 km/h) with respect to Earth. As Masi’s computerized telescope tracked its positionthe rock appeared stationary in the images while rendering the stars as these moving streaks.

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The gravitational kick that 2023 BU received during its encounter with Earth will alter the shape of its orbit around the sun. Previously, the space rock followed a rather circular orbit, completing one lap around the sun in 359 days. From now on, BU 2023 will travel through the inner solar system on a more elliptical path, venturing half way toward Mars at the farthest point of its orbit. This alteration will add 66 days to BU 2023’s orbital period.

The asteroid was discovered by famed Crimea-based astronomer and astrophotographer Gennadiy Borisov, the same man who in 2018 found the first interstellar comet, which now bears his name, Borisov.

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Green comet zooming our way, last visited 50,000 years ago

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This photo provided by Dan Bartlett shows comet C/2022 E3 (ZTF) on Dec. 19, 2022. It last visited during Neanderthal times, according to NASA. It is expected to come within 26 million miles (42 million kilometers) of Earth on Feb. 1, 2023, before speeding away again, unlikely to return for millions of years. Credit: Dan Bartlett via AP

A comet is streaking back our way after 50,000 years.

The dirty snowball last visited during Neanderthal times, according to NASA. It will come within 26 million miles (42 million kilometers) of Earth Wednesday before speeding away again, unlikely to return for millions of years.

So do look up, contrary to the title of the killer- movie “Don’t Look Up.”

Discovered less than a year ago, this harmless green comet already is visible in the northern night sky with binoculars and small telescopes, and possibly the naked eye in the darkest corners of the Northern Hemisphere. It’s expected to brighten as it draws closer and rises higher over the horizon through the end of January, best seen in the predawn hours. By Feb. 10, it will be near Mars, a good landmark.

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Skygazers in the Southern Hemisphere will have to wait until next month for a glimpse.

While plenty of comets have graced the sky over the past year, “this one seems probably a little bit bigger and therefore a little bit brighter and it’s coming a little bit closer to the Earth’s orbit,” said NASA’s comet and asteroid-tracking guru, Paul Chodas.

Green from all the carbon in the gas cloud, or coma, surrounding the nucleus, this long-period comet was discovered last March by astronomers using the Zwicky Transient Facility, a wide field camera at Caltech’s Palomar Observatory. That explains its official, cumbersome name: comet C/2022 E3 (ZTF).

On Wednesday, it will hurtle between the orbits of Earth and Mars at a relative speed of 128,500 mph (207,000 kilometers). Its nucleus is thought to be about a mile (1.6 kilometers) across, with its tails extending millions of miles (kilometers).

The comet isn’t expected to be nearly as bright as Neowise in 2020, or Hale-Bopp and Hyakutake in the mid to late 1990s.

Green comet zooming our way, last visited 50,000 years ago
This photo provided by Dan Bartlett shows comet C/2022 E3 (ZTF) on Dec. 19, 2022. It last visited during Neanderthal times, according to NASA. It is expected to come within 26 million miles (42 million kilometers) of Earth on Feb. 1, 2023, before speeding away again, unlikely to return for millions of years. Credit: Dan Bartlett via AP

But “it will be bright by virtue of its close Earth passage … which allows scientists to do more experiments and the public to be able to see a beautiful comet,” University of Hawaii astronomer Karen Meech said in an email.

Scientists are confident in their orbital calculations putting the comet’s last swing through the ‘s planetary neighborhood at 50,000 years ago. But they don’t know how close it came to Earth or whether it was even visible to the Neanderthals, said Chodas, director of the Center for Near Earth Object Studies at NASA’s Jet Propulsion Laboratory in California.

When it returns, though, is tougher to judge.

Every time the comet skirts the sun and planets, their gravitational tugs alter the iceball’s path ever so slightly, leading to major course changes over time. Another wild card: jets of dust and gas streaming off the comet as it heats up near the sun.

“We don’t really know exactly how much they are pushing this comet around,” Chodas said.

The comet—a time capsule from the emerging solar system 4.5 billion years ago—came from what’s known as the Oort Cloud well beyond Pluto. This deep-freeze haven for comets is believed to stretch more than one-quarter of the way to the next star.

While comet ZTF originated in our solar system, we can’t be sure it will stay there, Chodas said. If it gets booted out of the solar system, it will never return, he added.

Don’t fret if you miss it.

“In the comet business, you just wait for the next one because there are dozens of these,” Chodas said. “And the next one might be bigger, might be brighter, might be closer.”

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