Universe Today

December 13, 2012December 23, 2015 by John Williams

Hubble Census Unveils Galaxies Shining Near Cosmic Dawn

This new image of the Hubble Ultra Deep Field (HUDF) 2012 campaign reveals a previously unseen population of seven faraway galaxies, which are observed as they appeared in a period 350 million to 600 million years after the Big Bang. Credit: NASA, ESA, R. Ellis (Caltech), and the UDF 2012 Team

Astronomers using NASA’s Hubble Space Telescope have spotted some of the most distant, dim and ancient galaxies ever detected in a new survey. The images, taken with Hubble’s Wide Field Camera 3 (WFC 3) looks further back in time than any previous Hubble observation, providing information about the conditions in the early Universe.

“This is like a scientific version of the story of Genesis,” said astronomer Avi Loeb from Harvard University.

The seven distant galaxies represent a previously unseen population of galaxies that formed more than 13 billion years ago, when the Universe was less than 3 percent of its present age. In these deepest images to date from Hubble, astronomers were able to take a sample of the amount of galaxies at the time. The results show a smooth decline in the number of galaxies with increasing look-back time to about 450 million years after the Big Bang.

The data provides the first reliable census of this uncharted period of cosmic history, according to the scientists. As astronomers look even deeper into the Universe, galaxy numbers appear to drop off smoothly leading them to believe that the “cosmic dawn” was gradual, not a dramatic event.

“Observations of the microwave afterglow from the Big Bang tell us that reionization happened more than about 13 billion years ago,” said Brant Robertson of the University of Arizona in Tucson, a member of the survey team. “Our data confirms that reionization was a drawn-out process occurring over several hundred million years with galaxies slowly building up their stars and chemical elements. There wasn’t a single dramatic moment when galaxies formed; it was a gradual process.”

These galaxies were found as part of an ambitious Hubble survey of an intensively studied patch of sky known as the Ultra Deep Field (UDF), which was originally taken in 2003-2004, focusing in on a small area in the sky in the constellation Fornax. In the new 2012 campaign, called UDF 2012, a team of astronomers led by Richard Ellis of the California Institute of Technology used the WFC3 to peer deeper into space in near-infrared light than any previous Hubble observation. The observations were made over a period of six weeks during August and September 2012, and the first scientific results are now appearing in a series of scientific papers. The UDF 2012 team is publicly releasing these unique data, after preparing them for other research groups to use.

“Hubble is achieving just great science,” said John Grunsfeld, former astronaut and NASA’s associate administrator for science, speaking at a briefing about the new survey. “This is an origins story, where we’re going back to the beginning, back to the first stars that appeared in the Universe. This validates that when we get James Webb Space Telescope online it will have a lot to look at and a lot to do.”

The James Webb Space Telescope is slated to launch in 2018.

Astronomers detected seven galaxies in the time period 400-600 million years after the Big Bang. All extremely distant, they ranged in distance with redshifts from 8.6 to nearly 12.

Astronomers study the distant universe in near-infrared light because the expansion of space stretches ultraviolet and visible light from galaxies into infrared wavelengths, a phenomenon called “redshift.” The more distant a galaxy, the higher its redshift.

Notably, one of the galaxies may be a distance record breaker, observed 380 million years after the birth of our universe in the Big Bang, corresponding to a redshift of 11.9. This is the galaxy UDFj-39546284, which was previously detected and was originally suggested as the most distant object ever found nearly two years ago by Hubble. Later observations put it at a redshift of 10.3, but the newly refined observations put it even more distant.

A timeline of the Universe and our observations of it. Credit: University of Arizona.

Scientists think that the universe began with the Big Bang about 13.7 billion years ago. Hydrogen formed about 400,000 years later but with no stars, spacetime was dark. About 200 million years later, hydrogen clouds collapsed forming the first stars and galaxies; what astronomers call the “cosmic dawn.” Light from these new stars began breaking down hydrogen into protons and electrons during a time period called cosmic reionization. In the present universe, scientists see galaxies growing in mass and size with the synthesis of elements, leading to the formation of complex molecules including the components to create life. Our Sun and solar system formed just over 4 billion years ago.

“The team pushed Hubble to its limits. This is probably the farthest back Hubble can look, according to the study leader, Richard Ellis. “We are pushing Hubble well beyond what it was designed to do.”

Read the team’s paper: The Abundance of Star-Forming Galaxies in the Redshift Range 8.5 to 12: New Results from the 2012 Hubble Ultra Deep Field Campaign

Additional Sources: CalTech ESA Hubble

December 12, 2012December 23, 2015 by Nancy Atkinson

What Earth Looked like on 12/12/12

Earth, as seen by the GOES15 satellite on December 12, 2012. Credit: NASA/NOAA GOES Project/Dennis Chesters

Although we don’t subscribe to hokum like numerology or think that dates on a man-made calendar could have any sort of cosmic significance, there is something about a little symmetry. The GOES-15 satellite captured this image of Earth today, which is 12/12/12 on the Gregorian calendar, and even added a bonus of taking the image at 1200 UTC.

Too bad the GOES-12 spacecraft had some thruster problems and is currently in a standby mode.

Dennis Chesters, project scientist of NASA’s GOES Project at the NASA Goddard Space Flight Center said this image does something significant, however: the fourth tropical cyclone in the southern Pacific Ocean. Newborn Tropical Storm Evan was born today, Dec. 12, 2012 at 1500 UTC (10 a.m. EST) and appears as a rounded area of clouds in the bottom left corner of the image. Tropical Storm Evan is about 145 nautical miles west of Pago Pago, American Samoa.

See a larger version of this image here.

December 12, 2012December 23, 2015 by Nancy Atkinson

Asteroid Toutatis Tumbles by Earth: Images and Videos

Goldstone delay-Doppler radar images of Toutatis from December 11, 2012. Credit: NASA

While Asteroid 4179 Toutatis was never a threat to hit Earth during its quite-distant pass on Dec. 11-12, astronomers were keeping their instruments and eyes on this space rock to learn more about it, as well as learning more about the early solar system. Even at closest approach, 4179 Toutatis was 7 million km away or 18 times farther than the Moon. But that is close enough for radar imaging by NASA’s Goldstone Observatory, which has recently upgraded to a new digital imaging system, as well as optical imaging by other astronomers. Already, there are some preliminary findings from this 4.5-kilometer- long (3-mile-long) asteroid’s flyby.

“Toutatis appears to have a complicated internal structure,” said radar team member Michael Busch of the National Radio Astronomy Observatory. “Our radar measurements are consistent with the asteroid’s little lobe being ~15% denser than the big lobe; and they indicate 20% to 30% over-dense cores inside the two lobes.”

NASA says this raises the interesting possibility that asteroid Toutatis is actually a mash up of smaller space rocks. “Toutatis could be re-accumulated debris from an asteroid-asteroid collision in the main belt,” Busch said. The new observations will help test this idea.

Here are more images and video from Toutastis’ pass:

Adam Block from the Mount Lemmon SkyCenter/University of Arizona captured this footage:

Toutatis from Adam Block on Vimeo.

Astronomers are getting to know this asteroid, as it passes by Earth’s orbit every 4 years. It is one of the largest known potentially hazardous asteroids (PHAs), and its orbit is inclined less than half-a-degree from Earth’s. No other kilometer-sized PHA moves around the Sun in an orbit so nearly coplanar with our own. This makes it an important target for radar studies.

The team from the Remanzacco Observatory took this 120-second image of Toutatis:

Image from the ITelescope network (Nerpio, Spain) on 2012, Dec. 11.9, through a 0.15-m f/7.3 refractor + CCD. Credit: Ernesto Guido and Nick Howes/ Remanzacco Observatory.

And this was a fairly close pass for Toutatis: The next time Toutatis will approach at least this close to Earth is in November of 2069
when the asteroid will fly by at a distance of only 0.0198 AU (7.7 lunar distances).

NASA’s Goldstone radar in the Mojave Desert has been “pinging” the space rock every day starting on December 4, and will continue until the 22nd. The echoes highlight the asteroid’s topography and improve the precision with which researchers know the asteroid’s orbit.

Additionally, the Chinese Chang’e 2 spacecraft will be observing Toutatis tomorrow, on December 13, 2012 Chang’e 2 was originally launched to study the Moon but after completing its mission, Chang’e 2 departed from the L2 point in April 2012 to align itself to make a flyby of 4179 Toutatis, expected to take place at approximately 08:27 UTC on December 13.

“We already know that Toutatis will not hit Earth for hundreds of years,” said Lance Benner of NASA’s Near Earth Object Program.. “These new observations will allow us to predict the asteroid’s trajectory even farther into the future.”

Animation from Ernesto Guido and Nick Howes of 40 consecutive 10-second exposures. Credit: Ernesto Guido and Nick Howes/ Remanzacco Observatory.

NASA says the asteroid is already remarkable for the way that it spins. Unlike planets and the vast majority of asteroids, which rotate in an orderly fashion around a single axis, Toutatis travels through space “tumbling like a badly thrown football,” as Benner describes it. One of the goals of the radar observations is to learn more about the asteroid’s peculiar spin state and how it changes in response to tidal forces from the Sun and Earth.

Here’s an animation of Asteroid Toutatis compiled the live broadcast from the Slooh space camera team:

Goldstone delay-Doppler radar images of Toutatis from December 11, 2012. Credit: NASA

Sources: NASA, Remanzacco Observatory, Chang’e 2 mission

December 12, 2012January 4, 2016 by Nancy Atkinson

Google’s 2012 Year in Review Includes Space Highlights

Even though this is a promotional video by Google, it is a great review of 2012, good and bad. And there’s a plethora of space-related events and people featured. Look for: Felix Baumgartner’s jump, SpaceX’s Dragon launch, the search for the Higgs Boson, space shuttles, Curiosity’s landing, Neil Armstrong, Sally Ride, Ray Bradbury, the International Space Station, solar eclipse, and more.

As the Very Short List folks said, this video is “also an inspired reflection of our collective hopes, dreams, fears, and desires.”

December 12, 2012December 23, 2015 by Astronomy Cast

Podcast: Cosmological Constant

In order to allow for a static Universe, Albert Einstein introduced the concept of the Cosmological Constant Lambda to make the math work out. Once it was discovered that the Universe was actually expanding, he threw the number out calling it his “biggest blunder.” But thanks to dark energy, the Cosmological Constant is back.

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

“Cosmological Constant” on the Astronomy Cast website, with shownotes and transcript.

And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout:

December 11, 2012December 23, 2015 by Nancy Atkinson

How To Train for a Mission to the ISS: Medical Mayhem

Astronaut Chris Hadfield with biomedical equipment attached to his forehead. Credit: Chris Hadfield.

Canadian astronaut Chris Hadfield is scheduled to launch on Decemer 19 with crewmates Tom Marshburn and Roman Romanenko on a Soyuz rocket, heading for a long-duration 5-month mission on board the International Space Station. We’re taking a look back at his 2-plus years of training for this mission, which Hadfield shared via Twitter and Facebook, letting the public get an inside look at what it takes to prepare for a long-duration spaceflight.

The movie “The Right Stuff” depicted the grueling array of medical tests the early astronauts had to undergo in order to determine if they had… well, the right stuff to go into space. Now, more than 50 years later, with scientists and the medical community knowing quite a bit more about how the human body reacts to micro-gravity, the pre-flight medical procedures aren’t quite as intrusive. But astronaut Chris Hadfield says it is still part of being an astronaut.

“They do a nice job of telling how hard it is going to be, how invasive,” he said in an interview with Universe Today, “but none of that matters when it’s time to go to bed at night, when you’ve got six different probes stuck in you or a loud machine next to you, and you know you you’re not going to get a good night’s sleep.”

“Whether you are flying a spaceship or a T-38, it is good to be prepared,” Hadfield said, along with posting this image via Twitter.

Another part of medical training is having a forced special diet where “you have to document everything you eat, evaluating what happens at the other end,” Hadfield explained, “and they try to be as good and non-invasive as they can, but by its very nature it is invasive, and that’s the way it is.”

Hadfield said he knew about this going into the job. “It is absolutely part of the business so it is OK,” he said.

Hadfield participating in the VC Reflex test, an experiment for orthostatic hypotension, or dizzyness from low blood pressure, one of the most common physical complications of spaceflight. “Space Science: applying electricity behind the ears affects balance and thus blood pressure regulation,” Hadfield said.

Not only are there pre-flight medical tests and procedures, but all space station crew members undergo continual medical tests and evaluations during their time in orbit, becoming test subjects for various experiments as well as keeping tabs on their health while in space.

“We do regular urine, saliva collection and blood draws. We have to be able to take blood from each other or yourself. If you’ve never taken blood from yourself…” Hadfield said, letting the sentence trail off. Fun? Not so much.

“Astronaut physical for Space Station today – 18 tubes and a squeeze ball”

Thankfully, the astronauts don’t always have to poke themselves. “We have volunteers come in all the time and let me stick them with a needle so I can get good at drawing blood,” Hadfield said, “and we do a lot of ultrasounds – carotid artery and cardiac ultrasounds. We need to identify any changes that take place in the heart after extended zero-g. This is all very important for going beyond Earth orbit; we need to understand those changes.”

A day of medical training with dummies. “Somehow the sock makes it worse,” Hadfield said via Twitter.

Not only do the crew have to do medical tests on themselves, but they have to be prepared for any medical emergency, since there usually isn’t a dedicated medical doctor on the space station. However, Hadfield considers himself lucky: crewmate Marshburn is a medical doctor.

“There are various ways to get ill on board – some natural, like appendicitis, stroke, — or you could be in an accident.” Hadfield said, “Someone could bang their head coming around a corner, get pinched between equipment, get the bends coming in from a spacewalk, or be exposed to poisonous gas. Various things can happen.”

“We have full-911 capability on board,” Hadfield continued. “We can react, we can strap someone down, get them on oxygen, inject them with things to get their heart going again, or use defibrillators. We need to know how to intubate people and give them forced breathing. We need to know how to react.”

Medical training includes practicing emergency medical procedures such as stitches.

They have small pharmacy on board, and need to know a lot of procedures. “Of course we always have medical help on-call from the ground, but you could easily have to deal with a burn or something in an eye, so I’ve trained working in an emergency room at a hospital in Houston,” Hadfield said, doing things from making a quick diagnosis to inserting catheters or IVs, or sewing stitches on wounds “ so I can get comfortable doing those things to the human body.”

Astronauts on the ISS practicing CPR: “How do you give CPR without gravity to hold you down? Like this!,” Tweeted Hadfield.

This video shows some of the emergency medical training the crew receives:

Next: Astronaut Food

Additional articles in this series:
How to Train for Long Duration Space Flight with Chris Hadfield
How to Train for a Mission to the ISS: Medical Mayhem
How to Train for a Mission to the ISS: Eating in Space
How to Train for a Mission to the ISS: The Soyuz

December 11, 2012April 26, 2016 by Nancy Atkinson

Air Force’s Secret X-37B Space Plane Launches on Third Mission

Rising slowly on over 800,000 lbs of thrust, the Atlas V-OTV 3 mission begins. Credit: John O’Connor/nasatech

An Atlas V rocket launched from Cape Canaveral Air Force Station today, carrying the Air Force’s X-37B space plane into orbit on its third classified mission. Launch took place at 1:03 EST (18:03 UTC) for the unmanned Orbital Test Vehicle (OTV), which looks like a mini space shuttle.

The U.S. Air Force has not released any details of what may be on board the vehicle or what its mission may be. United Launch Alliance provided a webcast of the launch, but the broadcast was ended “at the request of our customer (the Air Force),” when the space plane successfully reached orbit.

See a video of the launch, below.

The X-37B is launched like a satellite and rides inside the fairing of the Atlas rocket. The X-37B can operate at in low Earth orbit for extended periods of time – the previous mission stayed in orbit for 469 days – and can re-enter Earth’s atmosphere and land on autopilot, landing just like a plane on a runway at Vandenberg Air Force Base in California.

Well into its roll program, the Atlas V-501 gracefully arcs across the blue skies. Credit: John O’Connor/nasatech

While looking much like the space shuttle, the X-37B is about 1/4 the size of NASA’s space shuttle’s and is built using composites lighter than aluminum, and it uses a new type of leading wing tiles, called Tough Rock, instead of the shuttle’s carbon-carbon tiles. It runs on solar power allowing for longer missions.

The plane itself is not so secretive – the Air Force has released images of it while it is on the ground – but its mission and payload are what are kept confidential. The mission could be Earth observation, surveillance or spying, or perhaps deploying a satellite.

A United Launch Alliance Atlas V is rolled to the pad at Space Launch Complex-41 in preparation for launch of the Air Force?s third Orbital Test Vehicle (OTV-3) mission. Credit: ULA

The launch was delayed several times so that ULA could investigate a glitch during a launch back in October.

“We had a little bit of concern with our upper stage engine, so we wanted to do some investigation and look into what was going on with that engine prior to (launch of the Orbital Test Vehicle),” said Jessica Rye, a ULA spokesperson.

In past missions, satellite watchers and amateur astronomers have kept tabs on the X-37B’s orbital whereabouts, and thanks to them, we expect to be able to provide small details about the space plane’s mission in the coming months.

More information: ULA

December 11, 2012December 23, 2015 by Nancy Atkinson

Stephen Hawking and CERN LHC Team Each Win $3 Million Prize

Stephen Hawking visited the Large Hadron Collider’s underground tunnel at Europe’s CERN particle physics research center in 2006. Hawking and seven CERN researchers receiving multimillion-dollar prizes from the Fundamental Physics Prize Foundation. Image credit: CERN

Two $3,000,000 special physics prizes have been awarded to Stephen Hawking and to seven scientists who led the effort to discover a Higgs-like particle at CERN’s Large Hadron Collider. The Fundamental Physics Prize Foundation, backed by Russian billionaire Yuri Milner announced the awards today, saying that Hawking is honored for his discovery of Hawking radiation from black holes “and his deep contributions to quantum gravity and quantum aspects of the early universe,” and that the prize money for the European Organization for Nuclear Research, or CERN, is being shared among a scientist who administered the building of the $10 billion Large Hadron Collider and six physicists who directed two teams of 3,000 scientists each.

The $3 million Fundamental Physics Prize is awarded annually by the nonprofit Fundamental Physics Prize Foundation to recognize “transformative advances in the field.” The $3 million prize may also be given at any time outside the formal nomination process “in exceptional cases,” according to the Foundation. When the Foundation’s prize intentions were announced in July of this year, Milner said, “I hope the new prize will bring long overdue recognition to the greatest minds working in the field of fundamental physics, and if this helps encourage young people to be inspired by science, I will be deeply gratified.”

The Foundation said the seven were being honored “for their leadership role in the scientific endeavor that led to the discovery of the new Higgs-like particle by the ATLAS and CMS collaborations at CERN’s Large Hadron Collider.” They will share the $3 million prize equally.

The laureates include Lyn Evans, a Welsh scientist who serves as the LHC’s project leader; Peter Jenni amd Fabiola Gianotti of the LHC’s ATLAS collaboration; and Michel Della Negra, Tejinder Singh Virdee, Guido Tonelli and Joe Incandela of the CMS collaboration.

“It is a great honour for the LHC’s achievement to be recognised in this way,” said CERN Director General Rolf Heuer in a statement. “This prize recognizes the work of everyone who has contributed to the project over many years. The Fundamental Physics Prize underlines the value of fundamental physics to society, and I am delighted that the Foundation has chosen to hold its first award ceremony at CERN.”

“I am very much pleased with the decisions of the Selection Committee,” commented Yuri Milner. “I hope that the prizes will bring further recognition to some of the most brilliant minds in the world and the great accomplishments they have produced.”

“Choosing this year’s recipients from such a large pool of spectacular nominations was a very difficult task,” said Nima Arkani-Hamed, a member of the Selection Committee. “The selected physicists have done transformative work spanning a wide range of areas in fundamental physics. I especially look forward to future breakthroughs from the first recipients of the New Horizons in Physics Prize.”

The laureates of 2013 New Horizons in Physics Prize are:

Niklas Beisert for the development of powerful exact methods to describe a quantum gauge theory and its associated string theory;

Davide Gaiotto for far-reaching new insights about duality, gauge theory, and geometry, and especially for his work linking theories in different dimensions in most unexpected ways;

Zohar Komargodski for his work on the dynamics of four-dimensional field theories. In particular, his proof of the “a-theorem” has solved a long-standing problem, leading to deep new insights.

Each of the laureates will receive $100,000.

Sources: Fundamental Physics Prize Foundation, IOP, CERN

December 11, 2012December 23, 2015 by Nancy Atkinson

Herschel Spacecraft Won’t “Bomb” the Moon, But GRAIL Will

Artist concept of Ebb and Flow, the two GRAIL spacecraft in orbit of the Moon. Credit: NASA

The Herschel space telescope is slated to be decommissioned next March as the observatory’s supply of cryogenic helium will be depleted. One idea for “disposing” of the spacecraft was to have it impact the Moon, a la the LCROSS mission that slammed into the Moon in 2009, and it would kick up volatiles at one of the lunar poles for observation by another spacecraft, such as the Lunar Reconnaissance Orbiter. However, that idea has been nixed in favor of parking Herschel in a heliocentric orbit. But don’t be disappointed if you were hoping for a little lunar fireworks. There will soon be a double-barreled event as the twin GRAIL spacecraft will impact the moon’s surface on December 17, 2012.

NASA will be providing more information about the GRAIL spacecrafts’ impacts at a briefing on Thursday, but the Gravity Recovery and Interior Laboratory (GRAIL) team said last week that they were still formulating ideas for the impact scenario, and looking at the possibility of aiming the crashes so they are within the field-of-view of instruments on LRO. The two spacecraft are running out of fuel – Principal Investigator Maria Zuber said they have to do three maneuvers every day to keep the spacecraft from slamming into the Moon on their own – and earlier this year the duo were lowered from their prime mission orbit of 55 kilometers above the Moon to 23 km, and this week were lowered to 11 km to enable even higher resolution data.

The two spacecraft have been providing unprecedented detail about the Moon’s internal structure as they send radio signals to each other and monitor any changes in distance between the two as they circle the Moon. Changes as small as 50 nanometers per second have been measured, and last week the team detailed how they were able to create the most detailed gravity map of the Moon, as well as make determinations that the Moon’s inner crust is nearly pulverized.

We’ll provide more information about the GRAIL impacts when it becomes available, but preliminary details are that the impacts will take place on Dec. 17 at 19:28 UTC (2:28 p.m. EST).

The impact by LCROSS (Lunar Crater Observation and Sensing Satellite) confirmed the presence of water ice and an array of volatiles in a permanently shadowed crater at the Moon’s South Pole, and it is expected GRAIL would be targeted for similar observations.

Artist’s concept of Herschel at the L2 libration point one million miles from Earth. Credit: ESA

The Herschel team had said earlier this year that because the cryogenic superfluid helium coolant is running out — and the spacecraft needs to be at temperatures as low as 0.3 Kelvin, or minus 459 degrees Fahrenheit to make its observations — one idea of getting rid of the spacecraft would be to impact it on the Moon. This week, they posted on the Herschel website that ‘the lunar impact option is feasible, but carries an additional cost on top of that of the heliocentric orbit option. The ESA Executive has decided that the Herschel spacecraft will be “parked” indefinitely in heliocentric orbit.”

The Herschel operational large halo orbit around L2 is unstable, and so the orbit needs regular “maintenance,” and consequently, after end-of-helium (expected in March 2013), the spacecraft will need to be “parked” somewhere else with no need of orbit maintenance.

Herschel team member Chris North told Universe Today that the mission operators needed to get some engineering tests done to determine if the Moon impact was feasible. “Basically they hand it over to engineers who do things that are considered too risky during the scientific mission itself – e.g. test the attitude control to its limits to see what it can withstand!” North said via email. He added that most people he had spoken with were all for the impact, — having it “go out in a blaze of glory.”

But, surprisingly, the costs for impact are greater than leaving it in a parking orbit for a few hundred years. It’s orbit may have to be maintained again in the future, as some estimates put it at potentially impacting Earth at some point in several hundred years.

And for anyone worried that a lunar impact by the GRAIL spacecraft will “hurt” the Moon, one look at the Moon shows that it has been hit in the past and continues to get impacted by asteroids and meteoroids, with no adverse affect to its orbit.

As LCROSS principal investigator Tony Colaprete said about the LCROSS impact, “What we’re doing with the Moon is something that occurs naturally four times a month on the Moon, whether we’re there or not. The difference with LCROSS is that it is specifically targeted at a certain spot, Cabeus crater,” and that the laws of physics mean there will be a miniscule perturbation.

Even though the Centaur rocket stage that hit the Moon was expect to kick up about 350 tons of lunar regolith, “The impact has about 1 million times less influence on the Moon than a passenger’s eyelash falling to the floor of a 747 jet during flight,” Colaprete said.

The two GRAIL spacecraft are about the size of washing machines, much smaller than the Centaur rocket, so will have less of an impact.

December 11, 2012December 23, 2015 by Nancy Atkinson

Close Approach Image of Asteroid 2012 XE54

Image of Asteroid 2012 XE54 taken with the the H06 ITelescope network near Mayhill, New Mexico on December 11, 2012, through a 0.25-m f/3.4 reflector + CCD. Credit: Ernesto Guido & Nick Howes, Remanzacco Observatory.

A newly discovered small asteroid named 2012 XE54 passed harmlessly by Earth early today and as predicted it was eclipsed by Earth’s shadow, causing its light to “wink out” for a short time, about 40 minutes.

Above is an image of the asteroid from Ernesto Guido and Nick Howes using a 0.25-m f/3.4 reflector + CCD with the ITelescope facility near Mayhill, New Mexico. It is a single 60-second exposure, “taken with the asteroid at magnitude ~13.2 and moving at ~630 “/min. The asteroid is trailed in the image due to its fast speed. At the moment of the close approach 2012 XE54 will move at ~ 720″/min… North is up, East is to the left,” wrote Guido and Howes on the Remanzacco Observatory website.

Below is an animation showing the movement of 2012 XE54, using three consecutive 60-second exposures. This asteroid was zipping right along at a fast pace, at a distance from Earth of about 226,000 km (141,000 miles) or about .6 lunar distances.

2012 XE54 Animation December 11, 2012, by E. Guido & N. Howes

Pasquale Tricarico of the Planetary Science Institute had predicted that the asteroid would pass through the Earth’s shadow, creating an asteroid eclipse, a rather rare event that is similar to an eclipse of the full Moon by Earth’s shadow. At 01:22 UTC on December 11 the eclipse began, and it left Earth’s shadow at 02:00 UTC. Those watching the asteroid noted that the asteroid “disappeared” from its track, and then reappeared after leaving Earth’s shadow.

“In two images taken at 01:30:16 and 01:31:18, 60sec exposure, 2012 XE54 appeared as a very faint and long track, then… nothing. In the following images there is no visible track. Wonderful!” wrote Elia Cozzi from the New Millennium Observatory, posting in the mpml asteroid research group message board.

Orbital diagram of Asteroid 2012 XE54 from JPL’s Small Body Database.

While we don’t have images to share of that event, as Guido and Howes mentioned, Peter Birtwhistle produced a lightcurve (see graph below) of the eclipse:

Tricarico wrote that the first known case of an asteroid being eclipsed by Earth’s shadow was “Asteroid 2008 TC3 which was totally eclipsed just one hour before entering Earth’s atmosphere over Sudan in 2008, and asteroid 2012 KT42 experiencing both an eclipse and a transit during the same Earth flyby in 2012.”

Guido and Howes also mentioned that their work last night was “in memory of our dear friend & colleague Giovanni Sostero.”