Connect with us

Science

Small asteroid becomes closest ever seen passing Earth: NASA – RFI

Published

on


Issued on: 19/08/2020 – 02:56

Advertising

Washington (AFP)

An asteroid the size of an SUV passed 1,830 miles (2,950 kilometers) above Earth, the closest asteroid ever observed passing by our planet, NASA said Tuesday.

If it had been on a collision course with Earth, the asteroid — named 2020 QG — would likely not have caused any damage, instead disintegrating in the atmosphere, creating a fireball in the sky, or a meteor, NASA’s Jet Propulsion Laboratory (JPL) said in a statement.

The asteroid, which was about 10 to 20 feet (three to six meters) long, passed above the southern Indian Ocean on Sunday at 0408 GMT.

It was moving at nearly eight miles per second (12.3 kilometers per second), well below the geostationary orbit of about 22,000 miles at which most telecommunication satellites fly.

The asteroid was first recorded six hours after its approach by the Zwicky Transient Facility, a telescope at the Palomar Observatory at the California Institute of Technology, as a long trail of light in the sky.

The US space agency said that similarly sized asteroids pass by Earth at a similar distance a few times per year.

But they’re difficult to record, unless they’re heading directly towards the planet, in which case the explosion in the atmosphere is usually noticed — as in Chelyabinsk, Russia in 2013, when the explosion of an object about 66 feet long shattered windows for miles, injuring a thousand people.

One of NASA’s missions is to monitor larger asteroids (460 feet) that could actually pose a threat to Earth, but their equipment also tracks smaller ones.

“It’s really cool to see a small asteroid come by this close, because we can see the Earth’s gravity dramatically bends its trajectory,” said Paul Chodas, the director of the Center for Near-Earth Object Studies at NASA.

According to the JPL’s calculations, the asteroid turned by about 45 degrees due to Earth’s gravitational pull.

Let’s block ads! (Why?)



Source link

Continue Reading

Science

Arctic Sea Ice at Second-Lowest Level in Satellite Record: Scientists – ChrisD.ca

Published

on


By Bob Weber, The Canadian Press

Sea Ice Ships are framed by pieces of melting sea ice in Frobisher Bay in Iqaluit, Nunavut on Wednesday, July 31, 2019. (THE CANADIAN PRESS/Sean Kilpatrick)

Satellite pictures show Arctic sea ice is at its second-lowest level since such records began and barely missed breaking the old mark.

“There’s no going back at this point,” said Mark Serreze of the U.S. National Snow and Ice Data Center.

“It’s not going to come back up.”

Although some melting might yet occur, the centre fixed Monday as the day when the overall level of all Arctic sea ice — crucial to northern ecosystems and southern weather patterns — stops shrinking and starts growing again.

Satellite images suggest the area at least 15 per cent covered by sea ice is now 3.7 million square kilometres.

That’s at least 1.5 million square kilometres less than the 1981-2010 median. It’s barely more than the all-time low in 42 years of satellite data, the 3.4 million square kilometres recorded in 2012.

All 14 of the lowest ice years on record have happened in the last 14 years, said Serreze.

Like 2012, this year’s low depended on a lot of things happening at once, Serreze said. That included an Arctic heat wave on the Siberian side, which helped create unprecedented fires across the Russian tundra.

The melt cost the Arctic much of its remaining multi-year ice, meaning the ice is increasingly seasonal. The old coverage of thick ice that survives the summer will soon be a thing of the past, said Serreze.

“I don’t think there’s any escaping that. It’s just too warm now.”

This summer, Canada’s last intact ice sheet — the Milne on Ellesmere Island — collapsed.

The implications are many, said David Barber, an Arctic systems scientist at the University of Manitoba.

“The ice controls the light and it controls the heat. We don’t find anything that isn’t affected.”

Whole ecosystems that hang on the bottom of the ice are disappearing. Invasive species from small fish to killer whales are moving in from both east and west.

Biologists have recently estimated that polar bears along south Hudson Bay will have trouble raising cubs by the end of the decade, due to the loss of their frozen hunting platform.

Less ice cover means bigger storm surges. Erosion on Arctic coastlines has more than doubled in the last few decades.

It also means the remaining ice has more room to drift, which leads to choking jams in places that don’t normally experience them.

“Some people locally will go, ‘Hold it. There’s all kinds of ice out here,’” Barber said. “That’s because it’s so much more mobile.”

Many scientists also believe sea ice matters to southern weather.

Published research suggests the strength of the jet stream — a high-atmosphere river of air that influences continental weather patterns — depends on the temperature difference between the Arctic and mid-latitudes. Less ice and a warmer Arctic Ocean means a weaker jet stream.

Any effects of melting sea ice are likely to increase. Open ocean absorbs more sunlight than water covered by reflective ice, so heavy melt years create a feedback loop.

“That (open water) is absorbing all that heat and you have to get rid of it in the fall before you can start to form ice,” Barber said. “Which means you’ll have a thinner ice cover.”

CP - The Canadian Press

CP - The Canadian Press

Let’s block ads! (Why?)



Source link

Continue Reading

Science

Celebrate Virtual International Observe the Moon Night with NASA Goddard – Stockhouse

Published

on


PR Newswire

WASHINGTON , Sept. 22, 2020 /PRNewswire/ — The public is invited to virtually attend NASA’s Goddard Space Flight Center’s International Observe the Moon Night on Saturday, September 26 from 7-8 p.m. EDT . The event will feature engaging pre-recorded content – presentations, demonstrations, video clips – and a question-and-answer session with NASA scientists and engineers.

Presentation content will be streamed via NASA TV, the Goddard Visitor Center Facebook page and on the NASA Goddard YouTube channel . NASA experts will be online throughout the event to answer questions. There will be about 40 minutes of pre-recorded content and then 20 minutes of dedicated Q&A with NASA scientists/engineers.

The agenda includes:

  • Lunar videos
  • Demonstration on volcanoes and how to build your own volcano at home
  • Discussion on geology and the elements of art
  • Presentation on SOFIA and its connection to Artemis and lunar water

International Observe the Moon Night is a global celebration of lunar and planetary science and exploration, celestial observation, and personal and cultural connections to the Moon. It occurs annually in September or October, when the Moon is around first quarter ― a great phase for evening observing.

International Observe the Moon Night is sponsored by NASA’s Lunar Reconnaissance Orbiter (LRO) mission and the Solar System Exploration Division of NASA’s Goddard Space Flight Center, with many contributors. LRO is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland , for the Science Mission Directorate at NASA Headquarters in Washington, D.C.

No registration is needed.

For more information about International Observe the Moon Night, visit: https://moon.nasa.gov/observe

For more information about LRO, visit: https://www.nasa.gov/lro

For more information on the Moon, visit: https://moon.nasa.gov

Cision View original content to download multimedia: http://www.prnewswire.com/news-releases/celebrate-virtual-international-observe-the-moon-night-with-nasa-goddard-301135661.html

SOURCE NASA

Let’s block ads! (Why?)



Source link

Continue Reading

Science

‘Mini-moon’ set to join Earth might be a rock — or something more – Global News

Published

on


Earth and the moon have had a pretty steady relationship over the last 4.53 billion years, but our planet is about to have a close encounter with another body in space, according to astronomers’ projections.

A small object is expected to fall into Earth’s orbit in October, when it will potentially become a so-called “mini-moon” for the next several months. The new object, dubbed 2020 SO, will loop around the Earth in a figure-eight before spinning back into space in May 2021, according to NASA tracking data. The space agency has dubbed it an Apollo object, meaning it’s expected to cross Earth’s orbit.

Read more:
They shall call it ‘mini-moon’ — car-sized object found orbiting Earth

Most space objects are asteroids, but astronomers say there’s something unusual about this one. They say it’s no mini-moon — it’s a piece of space trash. More specifically, it might be a discarded Centaur rocket booster from the Surveyor 2 robot that crash-landed on the moon in September 1966.

Story continues below advertisement

Whatever it is, it could become the second mini-moon in Earth’s orbit this year after 2020 CD3, a car-sized bit of space rock, left us in February. That mini-moon quietly circled Earth for about two years, though astronomers didn’t spot it until shortly before it left.

This one is on course to become a mini-moon but it has a “highly chaotic path,” according to Tony Dunn, who runs the website Orbit Simulator.

Mini-moons are extremely rare despite our luck with them this year. Earth’s gravity will typically pull a space rock down as a meteor or bend its trajectory before releasing it into space. However, space objects can do a few loops around our planet if they approach it just right.

Story continues below advertisement

That’s what happened with 2020 CD3 earlier this year. Earth also hooked up with another asteroid, dubbed 2006 RH120, for a brief mini-moon fling through space 14 years ago.

There’s still no guarantee that the object will become a mini-moon, as Lisa Harvey-Smith, an astrophysicist with the Australian government, pointed out on Twitter.






0:41
India loses contact with space craft heading for moon


India loses contact with space craft heading for moon

The object is expected to come within 50,000 kilometres of Earth on its first pass, and within 220,000 kilometres for its second close encounter. Both passes will bring it closer to Earth than the moon.

This object would become our third mini-moon in recent memory — and perhaps the first one made by humans.

The strongest indicator that it’s not an asteroid is the low velocity, according to Alice Gorman, a space archaeologist at Flinders University in Australia.

Story continues below advertisement

“What I’m seeing is that it’s just moving too slowly, which reflects its initial velocity,” she told ScienceAlert. “That’s essentially a big giveaway.”

Read more:
Aliens over Venus? Astronomers catch a whiff of life in planet’s clouds

The object is between 6.4 and 14 metres long, according to NASA.

The Centaur rocket booster was 12.68 metres long, and it helped propel the Surveyor 2 lander to the moon exactly 54 years ago. The lander jettisoned the booster into space during the mission.

This 1963 photograph shows vent flowing cryogenic fuel and T/C Rake mounted on a 1/10 scale model Centaur rocket in the Supersonic Wind Tunnel at the Glenn Research Center.


This 1963 photograph shows vent flowing cryogenic fuel and T/C Rake mounted on a 1/10 scale model Centaur rocket in the Supersonic Wind Tunnel at the Glenn Research Center.


NASA

Gorman says that if it is an old piece of human technology, she’d like to scan it to see how much damage it’s sustained after half a century in space.

Story continues below advertisement

“It’s human material that’s been out in a different part of space,” she said.

“It would be interesting to compare that to the results you get from stuff in low Earth orbit, which is much, much denser material.”

The object is expected to approach Earth on Oct. 1.

© 2020 Global News, a division of Corus Entertainment Inc.

Let’s block ads! (Why?)



Source link

Continue Reading

Trending