Science
Palomar Observatory Detects Flash From a Black Hole Swallowing a Star


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Do we have enough astronomers researching the universe?
This discovery happened earlier this year through an all-sky survey at the Palomar Observatory in California. An all-sky survey is a relatively low cost way of monitoring the whole sky for this exact purpose — to detect and investigate photometric variability. Photometric variability is any change in the perceived brightness of light. So, if we are looking at stars very far away, we can measure their perceived brightness over time, and then record any changes.
This particular detection was in a part of the sky where nothing had been observed before. After detecting the flash, the astronomers from NASA and Caltech posted this discovery to an astronomy newsletter. This discovery over course got the attention of many around the world. You could say it turned heads, or more accurately it turned telescopes. In a matter of days, more telescopes had honed in to collect more data.
“Now, the MIT astronomers along with their collaborators have determined a likely source for the signal. In a study appearing today in Nature Astronomy, the scientists report that the signal, named AT 2022cmc, likely comes from a relativistic jet of matter streaking out from a supermassive black hole at close to the speed of light. They believe the jet is the product of a black hole that suddenly began devouring a nearby star, releasing a huge amount of energy in the process.
Astronomers have observed other such “tidal disruption events,” or TDEs, in which a passing star is torn apart by a black hole’s tidal forces. AT 2022cmc is brighter than any TDE discovered to date. The source is also the farthest TDE ever detected, at some 8.5 billion lights years away — more than halfway across the universe.” — MIT
This is an exciting discovery, but perhaps the most interesting observation is that the black hole’s jet might be pointing directly at Earth. Maybe we have something heading our way? In any case, this discovery illuminates a need to continue to develop more powerful telescopes and grow the number of astronomers in our society.
Consider the amount of human capital and resources it took to detect and investigate this flash of light. From the relatively low cost all-sky survey to the probably hundreds of researchers that were activated to investigate, this was a sizeable effort. And, there are also opportunity costs to investigating any particular flash of light. There is a lot happening in the universe, and we need to be able to detect and investigate in many areas simultaneously. It is impressive that we coordinated a global network of telescopes to investigate this flash of light. What else could we do with an even more advanced and larger global network of astronomers and telescopes?
Science
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.
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.




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


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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-comet 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.
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.


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 solar system‘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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Science
University of Guelph students are in the race to grow food in space

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Growing food in space is a complex challenge, but students at the University of Guelph have a pretty good idea of how to go about it.
The team, Canada GOOSE — which stands for Growth Options for Outer Space Environments — is among five teams across Canada, including the University of Waterloo, competing in the multi-year competition from the Canadian Space Agency (CSA) known as the Deep Space Food Challenge.
The team is currently on the second phase of the competition and hosted representatives from CSA on Thursday to showcase their idea.
The teams have been instructed to develop new technologies that would be able to produce food in space, but that could also be used for production here on Earth.
The Canada GOOSE team uses a hydroponic-like, high-density system to produce several kinds of fruits, vegetables and mushrooms.
“We have a multi-tier system growing a variety of plants, but the whole environment is being controlled so, air circulation, temperature, CO2 level, also light levels with the LEDs. So basically giving the best conditions for the plants to grow,” explained Serge Levesque, a second-year PhD student.
Rosemary Brockett, a second year masters student, explained the crops were developed and grown to produce as little waste as possible.
“We can’t have any kind of waste in space or in remote areas so we’re growing them all using fabric wicks,” she said.
“The fabric pulls up the water to the plants and then we have 3D-printed holders that support the plants and the fabric.”
Brockett said they can grow root vegetables like turnips and carrots; dwarf tomatoes and peppers; leafy greens like cabbage, lettuce and bok choy; smaller trays have herbs, radish microgreens and sprouts.
Levesque said they also grow mushrooms because they play a key role in the unit’s ecosystem.
“Plants photosynthesize and release oxygen and mushrooms need oxygen to release CO2, so it allows us to use CO2 more efficiently,” he said, adding the inedible parts of other vegetables can be used to help grow the mushrooms; a way to re-use and eliminate waste.


Tech can help feed, educate Earthlings
The Canadian grand prize won’t be announced until Spring 2024, but no matter the results, the students see applications for their technology closer to home.
First-year PhD student Ajwal Dsouza says it could be a useful education tool for youth, for example.
“Imagine putting this system up in a school or a university and educate people about the technological advancements happening but also [encourage] younger generations to study this,” and can also imagine applications in addressing food insecurity in other more remote parts of the world, like Canada’s northern communities.
“A system like this can be economically feasible. You can use it in remote areas where there is food insecurity using limited resources,” he said.
“We can grow food in places where the weather is not good, like Canada’s north or in a desert, where there’s limited resources. This can help people grow food in tough conditions,” said Dsouza.
The Canada GOOSE team will find out if they enter the third stage of the competition in March.




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