Asteroid 2012 QG42 Zooms by Earth Tonight — Watch Live!

A newly found asteroid will zip past Earth tonight (Sept. 13/14). But don’t worry; at a distance of 2.85 million km (1.7 million miles) Asteroid 2012 QG42 will safely pass by Earth. But that’s close enough for this space rock to be considered a Potentially Hazardous Asteroid (PHA) which means it may pose a threat in the future. This asteroid is between 190 to 430 meters (625 feet to 1,400 feet) wide and was first spotted by astronomers at the Catalina Sky Survey in Arizona on August 26. NASA’s Near Earth Object Office said they will use this opportunity to observe the asteroid with radar – which is a great way to find out about the physical properties and orbits of asteroids.

Closest approach is on September 14 at 05:08 UT (1:08 am EDT)

Amateur and professional astronomers have already been keeping tabs on this asteroid. Above is a timelapse from Peter Lake. And a couple of different live feeds from telescopes will be available to watch the action.

The Virtual Telescope Project run by astronomer Gianluca Masi in Italy is already providing a live video stream at http://www.virtualtelescope.eu/webtv/

Additionally, the Slooh Space Camera night sky observing website will provide a live view of asteroid 2012 QG42’s closest approach in a webcast starting at 7 p.m. EDT (2300 GMT) on Sept. 13, offering views from at least one of its telescopes at its observatory in the Canary Islands, off the west coast of Africa. You can watch the Slooh webcast by visiting their website here: http://www.slooh.com

A view of Asteroid 2012 QG42 from the Siding Spring-Faulkes Telescope South on 2012, September 4, 2012, through a 2.0-m f/10.0 Ritchey-Chretien + CCD, a stack of 4×10-second exposures, taken with the asteroid at magnitude ~15.2 and moving at 4.35″/min. Credit: Ernesto Guido, Nick Howes & Giovanni Sostero.

Asteroid 2012 QG42’s flyby comes a few months after another recently discovered space rock, asteroid 2012 LZ1, made its closest approach to Earth just days it was discovered.

“Near-Earth objects have been whizzing past us lately, undetected until they have been practically on top of us,” said Bob Berman, Slooh commentator and Astronomy Magazine writer. “This illustrates the need for continued and improved monitoring for our own future safety. It is not a question of if, but when such an object will hit us, and how large and fast it may be going.”

Slooh will be using at least three of its online robotic telescopes to provide live image feeds as the celestial intruder makes its closest approach to Earth throughout the night.

At a magnitude of only 13-14, about the same faintness as the demoted ex-planet Pluto, the asteroid is a challenging target for backyard telescopes. To observe this kind of object requires large telescopes, equipped with ultra-sensitive CCD cameras, carefully set-up to point and track such a fast moving object — Slooh’s Half Meter Telescope at its Canary Islands Observatory is perfect for the task, the Slooh team said.

“To observe them — as we will do live on Thursday evening,” said Berman, “provides instruction and perhaps motivation to keep up our guard, as well as a sense of relief as it speeds safely past at a mere one fifteenth the distance to the nearest planets.”

With the radar images that NASA plans to take, the “echo”measurements can produce two-dimensional images that can provide spatial resolution as fine as a decameter if the echoes are strong enough. With enough data, astronomers can construct detailed three-dimensional models, define the rotation state precisely, and constrain the object’s internal density distribution.

So look for more information on this asteroid after it passes by Earth.

Dawn’s Parting Shots of Vesta

Dawn’s look at asteroid Vesta as the spacecraft heads off to Ceres. Image credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA

As Dawn says goodbye to Vesta — where the spacecraft has been orbiting for over a year — here are two final views of the giant asteroid, which are among the last taken by the spacecraft, NASA said.

“Dawn has peeled back the veil on some of the mysteries surrounding Vesta, but we’re still working hard on more analysis,” said Christopher Russell, Dawn’s principal investigator at UCLA. “So while Vesta is now out of sight, it will not be out of mind.”

The first is a black-and-white mosaic that shows a full view of the giant asteroid, created by synthesizing some of Dawn’s best images.

Below is a color-coded relief map of Vesta’s northern hemisphere, from the pole to the equator. It incorporates images taken just as Dawn began to creep over the high northern latitudes, which were dark when Dawn arrived in July 2011.

These color-shaded relief maps show the northern and southern hemispheres of Vesta, derived from images analysis. Colors represent distance relative to Vesta’s center, with lows in violet and highs in red. In the northern hemisphere map on the left, the surface ranges from lows of minus 13.82 miles (22.24 kilometers) to highs of 27.48 miles (44.22 kilometers). Light reflected off the walls of some shadowed craters at the north pole (in the center of the image) was used to determine the height. In the southern hemisphere map on the right, the surface ranges from lows of minus 23.65 miles (38.06 kilometers) to 26.61 miles (42.82 kilometers).

The shape model was constructed using images from Dawn’s framing camera that were obtained from July 17, 2011, to Aug. 26, 2012. The data have been stereographically projected on a 300-mile-diameter (500-kilometer-diameter) sphere with the poles at the center.

The three craters that make up Dawn’s “snowman” feature can be seen at the top of the northern hemisphere map on the left. A mountain more than twice the height of Mount Everest, inside the largest impact basin on Vesta, can be seen near the center of the southern hemisphere map on the right.

These images are the last in Dawn’s Image of the Day series during the cruise to Ceres. A full set of Dawn data is being archived at http://pds.nasa.gov/ .

Wanted: Asteroid Mappers to Help Scientists Delve Through Data from Dawn

Many types of craters are captured in this panorama of recent Dawn images. Credit: NASA

There’s a new citizen science project in town, and this one will allow you to be among the first to see high-resolution, stunning images of Vesta from the Dawn mission. Called AsteroidMappers, the project asks the public to help the Dawn mission scientists to identify craters, boulders and other features on Vesta’s surface. “If you’ve already been addicted to MoonMappers, you’ll be even more addicted to AsteroidMappers!”said Nicole Gugliucci from CosmoQuest, home to several citizen science projects.

As you know, Dawn has been in orbit of the asteroid Vesta, but just recently left orbit and is now on its way to Ceres. This is a first in space exploration, where a spacecraft orbits one body and then leaves to go on to another. This can only be accomplished because of Dawn’s revolutionary ion engine.

The goal of the Dawn mission is to characterize the conditions and processes of the solar system’s earliest epoch by investigating in detail two of the largest protoplanets remaining intact since their formations. Ceres and Vesta both reside in the asteroid belt, but yet each has followed a very different evolutionary path constrained by the diversity of processes that operated during the first few million years of solar system evolution.

Even the Dawn scientists have been amazed at what they’ve seen at Vesta.

“We have acquired so much more data than we had planned even in late 2011,” Dr. Marc Rayman, the mission’s Chief Engineer, told Universe Today in a previous article. “We have conducted a tremendous exploration of Vesta – the second most massive body between Mars and Jupiter, a giant of the main asteroid belt.”

With AsteroidMappers (Vesta Edition), you’ll be helping the Dawn scientists learn more – not only about Vesta, but about how our solar system evolved.

As with every CosmoQuest project, there is a tutorial to help you get started. But the work area is fairly intuitive, with instructions and hints along the way.

The Dawn scientists have not yet released to the public all the images, so by working on this citizen science project, you’ll be looking at pristine images that perhaps no one else has seen before. The images are absolutely beautiful, as Vesta has turned out to be even more fascinating than expected, with huge impact basins, steep cliffs and unusual features on its surface.

“Vesta is unlike any other object we’ve visited in the solar system,” said Dawn mission team member Vishnu Reddy. “We see a wide range of variation on the surface, with some areas bright as snow, and other areas as dark as coal.”

Scientists have said that Vesta more closely resembles a small planet or Earth’s Moon than another asteroid, and they now have a better understanding of both Vesta’s surface and interior, and can conclusively link Vesta with meteorites that have fallen on Earth.

So, check out AsteroidMappers and enjoy the views! As @therealjason said on Twitter, “I don’t map Vesta very often, but when I do, I choose @cosmoquestX – Stay curious, my friends.”

Learn more about the Dawn mission here.

Students: Asteroid 1999 RQ36 Needs a New Name!

NASA and the Planetary Society are giving students worldwide the opportunity to name an asteroid. And it’s not just any asteroid; an upcoming NASA mission will return samples of this asteroid to Earth. The Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer (OSIRIS-REx) will be heading to an asteroid, currently named (101955) 1999 RQ36. The poor asteroid just needs a name that is a little more exciting and user-friendly – something that is easy to remember!

Scheduled to launch in 2016, the mission could hold clues to the origin of the solar system and organic molecules that may have seeded life on Earth. NASA also is planning a crewed mission to an asteroid by 2025. A closer scientific study of asteroids will provide context and help inform this mission.

“Because the samples returned by the mission will be available for study for future generations, it is possible the person who names the asteroid will grow up to study the regolith we return to Earth,” said Jason Dworkin, OSIRIS-REx project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md.

The competition is open to students under age 18 from anywhere in the world. Each contestant can submit one name, up to 16 characters long. Entries must include a short explanation and rationale for the name. Submissions must be made by an adult on behalf of the student. The contest deadline is Sunday, Dec. 2, 2012.

See here for contest rules and instructions.

Simulated asteroid image – topography overlaid on radar imagery of 1999 RQ36. Credit: NASA/GSFC/UA

The contest is also sponsored by the Massachusetts Institute of Technology’s (MIT) Lincoln Laboratory in Lexington; and the University of Arizona in Tucson.

A panel will review proposed asteroid names. First prize will be awarded to the student who recommends a name that is approved by the International Astronomical Union Committee for Small-Body Nomenclature.

“Our mission will be focused on this asteroid for more than a decade,” said Dante Lauretta, principal investigator for the mission at the University of Arizona. “We look forward to having a name that is easier to say than (101955) 1999 RQ36.”

The asteroid was discovered in 1999 by the Lincoln Near Earth Asteroid Research (LINEAR) survey at MIT’s Lincoln Laboratory. LINEAR is part of NASA’s Near Earth Observation Program, Washington, which detects and catalogs near-Earth asteroids, and comets. The asteroid has an average diameter of approximately 500 meters (1,640 feet).

“We are excited to have discovered the minor planet that will be visited by the OSIRIS-REx mission and to be able to engage students around the world to suggest a name for 1999 RQ36,” said Grant Stokes, head of the Aerospace Division at MIT Lincoln Laboratory and principal investigator for the LINEAR program.

The asteroid received its designation of (101955) 1999 RQ36 from the Minor Planet Center, operated by the Smithsonian Astrophysical Observatory in Cambridge, Mass. The center assigns an initial alphanumeric designation to any newly discovered asteroid that once certain criteria are met to determine its orbit.

“Asteroids are just cool and 1999 RQ36 deserves a cool name!” said Bill Nye, chief executive officer for The Planetary Society. “Engaging kids around the world in a naming contest will get them tuned in to asteroids and asteroid science.”

Click here for more info about the OSIRIS-Rex mission

Desert RATS Begin Simulated Asteroid Mission Today

Caption: Artist’s Concept, Space Exploration Vehicle Use Comparison. Credit: NASA

Conspiracy theories abound that the Apollo landings all took place on a film set in California, but today NASA’s Desert RATS team begins a mission to asteroid Itokawa. They will land, rove and even undertake spacewalks, without ever stepping foot out of their home base at Johnson Space Center in Texas. This is no hoax however, but a simulated mission to test out NASA’s audacious plan to send astronauts to an asteroid by 2025.

The Desert RATS have been testing robots and other tools that could be used on future exploration missions since 1997, (this is their 15th mission) usually doing analog missions out in the field. “Desert” refers to the Arizona desert, where a lot of the team’s activities take place and “RATS” stands for “Research and Technology Studies.”

However, since they are now testing out a zero-G visit to an asteroid, the team will use mockups inside JSC’s Space Vehicle Mockup Facility, which offers a medley of tools and simulators that would be difficult to transport to a field test location.

For example, the Multi-Mission Space Exploration Vehicle (MMSEV) is designed to both rove across a planetary surface on a wheeled chassis or fly in space using advanced propulsion systems. Four crew members will take it in turns to live in and operate the simulator to explore the asteroid.

The MMSEV can be put on a sled on an air-bearing floor to simulate the moves that the crew might feel during a real mission. There will also be a 50-second delay in voice transmission, going each way to simulate the light-speed travel time between Earth and the asteroid.

The crew can also undertake spacewalks using ARGOS (Active Response Gravity Offload System) an overhead gantry crane system that simulates the reduced gravity environment. In reality nothing would stop astronauts from just floating off the surface but NASA is thinking about using jetpacks, tethers, bungees, nets or spiderwebs to allow them to float just above the surface attached to a smaller mini-spaceship.

A team of scientists from the Astromaterials Research and Exploration Science Directorate will ensure proper scientific methods are applied to asteroid sample collection techniques throughout the 10 day mission.

The mission is slated to run until August 30th or 31st. Find out more here or follow the NASA Desert RATS team on Twitter

Second image caption: ARGOS can be used to make spacewalkers feel as though they weigh 1/6 of their weight, as they would on the moon, or 1/3, as on Mars. Photo credit: NASA

Schweickart: Private Asteroid Mission is for the Benefit of Humanity

The B612 Foundation announced in June of this year that it plans to launch the first privately funded deep space mission, a space telescope that will map the inner solar system’s asteroid population and chart their orbits over the next hundred years. The goal is to find every potentially Earth-impacting object out there.

“This is a very practical — and necessary — project,” Rusty Schweickart, Chairman Emeritus of B612, and Apollo 9 astronaut told Universe Today. “It can be done, it is exciting and we are trying to get the world to recognize that this is a great investment in the future of humanity.”

Caption: Sentinel’s field of view. Credit: B612 Foundation.

The spacecraft is called Sentinel, and it will be equipped with a 20.5-inch cryo-cooled infrared telescope that will scan for space objects such as asteroids and comets. It will be placed in orbit around the Sun, ranging up to 170 million miles from Earth, for its mission of discovery and mapping.

B612 Foundation is nonprofit group of scientists and explorers who advocate exploration of asteroids and monitoring of their trajectories to protect the Earth from potentially catastrophic impacts. Other notable members of the Foundation include space shuttle and International Space Station astronaut Ed Lu (B612’s CEO), project architect Scott Hubbard, a Stanford professor who once served as the head of NASA’s Mars’ missions, and mission director Harold Reitsema, former director of space science missions at Ball Aerospace.

The foundation is named after the asteroid in Antoine de Saint-Exupery’s story “The Little Prince” which brought the young prince to various destinations, and originally the B612 Foundation focused on determining the best ways for deflecting a potential incoming asteroid. But it has since shifted its focus to the current project which involves only identifying dangerous near-Earth objects.

Read a new article, “Chasing the Little Prince in New York City”

“We have been working this issue for a number of years,” Schweickart said via phone, “and finding these asteroids is the next step that everyone agrees needs to be done.”

Schweickart said for years, the expectations were that NASA would be doing a project like this.

“But you know the situation in Washington,” he said. “With NASA’s budgeting outlook and the priorities NASA currently has, it doesn’t appear like this is something NASA could get to for a long time. We decided that, given what is going on with privatizations and with launch costs coming down, this was something on the scale that could be privately these days. And in recognizing the delay of not doing it ourselves, we decided to give it a go.”

While NASA’s Near-Earth Object program is scanning the skies and has found nearly 10,000 objects, or about 90 percent of the estimated objects larger than a half-mile across, according to B612, there are a half million more asteroids larger than the one that devastated the Tunguska region in northern Russia in 1908. Of those, only one percent has been mapped.

Schweickart said the launch of Sentinel would be a seminal step.

“It is the big step to locate almost all the objects of a size that can really do damage on the surface,” he said. “In five and a half years, we can meet very rapidly the goal of 90% of 140-meter-wide objects. But going down to the smaller ones that can still do damage, like the size of Tunguska, we should have about 50% of those that five and a half years. If we end up with an extended mission, which we’d definitely like to do, we should get to 60-70% completion of objects down to 40 meters.”

That would put over 500,000 objects in the Near Earth Object database, and Scheickart said, “the nice thing about asteroids is that once you’ve found them and once you have a good solid orbit on them you can predict a hundred years ahead of time whether there is a likelihood of an impact with the Earth.”

The Sentinel spacecraft is being built by Ball Aerospace and has been described as a mash-up of the Spitzer and Kepler space telescopes, both also designed by Ball. It’s wide-field, 24-million-pixel view should be able to map asteroids down to 40 meters.

B612 is targeting launch for 2017-2018, and their launch vehicle of choice is the SpaceX Falcon9.

Schweickart said Ball Aerospace has been working on the concept and design of this type of telescope for several years. “And we’ve been working with them on a daily basis for over a year now, so we are pretty confident that they can build this and we can launch and operate it,” he said, “but the new part of the challenge is raising the money.”

Currently B612 has specialists working on their funding, “and that is sufficient for now,” Schwieckart said. “As we move forward the costs will dramatically increase, no question. When you start bending metal and building spacecraft, and buying launch services you are talking a few hundred million dollars. But with anything like this, you raise that in stages.”

Since the announcement of the Sentinel mission comes closely on the heels of the Planetary Resources’ announcement of their own plans to privately travel to asteroids to mine them for minerals, Universe Today asked Schweickart to compare the Sentinel to Planetary Resource’s plans.

“Their plan is completely different,” Schweickart said. “We don’t have any relationship with them, but we’ve certainly talked with them. They are interested in developing resources from asteroids, and doing specific site surveillance of particular asteroids that they might want to use for resource development. But they have to know where to go. And our job is to find asteroids and map this territory – which is basically a region like a ‘donut’ around the Earth, so Planetary Resources will be consulting our maps, as many other people will, as well.”

And Schweickart added, “Our project has nothing to do with profit or investment for payback. This is for the survival and the benefit of humanity – everyone on Earth.”

But Schweickart called this territory of asteroids “the new frontier,” and protecting Earth is not the only reason for mapping asteroids. “It is not just planetary defense, it is also resources in the future, and places for human exploration, and it is science as well. We are going to end up with a map that can be used by many people.”

How difficult will it be for the Sentinel mission to be successful?

“You are talking to a technologist,” Schweickart said with a chuckle. “To me the technology is pretty straightforward, and we’ve got that pretty much in hand. But it is a different kind of project than what has been done before, so that is where the challenge lies. But I think this will be a very exciting process.”

For more information on the B612 Foundation and the Sentinel project and how you can donate, see the B612 Foundation website, or watch the video below.

Watch A Near Earth Asteroid Zoom By

Caption: A view of asteroid 2002 AM31 on Friday, July 20 2012, at 08:34 UT by the Faulkes Telescope North. Credit: Las Cumbres Observatory Global Telescope Network.

An asteroid will pass by Earth on July 22, and thanks to the Slooh Space Camera you can watch it zoom by. There’s absolutely no chance this asteroid, named 2002 AM31, could hit Earth, as it is passing by at 14 times the distance of the Moon. But it should be interesting to watch the action live! As they have done with recent asteroid close passes, Slooh live-stream telescope views of the near-approach of this city-block-sized asteroid at http://www.slooh.com, starting at 4:30 p.m. PDT / 7:30 p.m. EDT / 23:30 UTC — accompanied by real-time discussions by Slooh’s Patrick Paolucci and Astronomy magazine columnist Bob Berman.

The asteroid is estimated to be 620 m to 1.4 km (2,000 to 4,500 ft wide) and will pass within 14 times the Moon’s distance from our planet.

Due to its size and proximity to Earth, 2002 AM31 qualifies as a near-Earth object as it’s more than 500 feet wide and within 4.65 million miles of Earth.

“Near Earth objects are no longer treasures only for the paranoid, or for those who secretly and strangely are rooting for an early apocalypse,” said Berman. “The entire astronomical community has reversed its thinking about them over the past few decades. Instead of living on an “island Earth” with little or no connection with other celestial objects, we now feel that collisions with comets or asteroids change the evolution of our biosphere, and maybe even seeded our world with the amino acids that started life long ago. In other words, these are important entities. Not to mention, there’s always that exciting little hint of danger.”

“One of our missions at Slooh is to provide the public with free, live views on fascinating celestial happenings,” says Patrick Paolucci, President at Slooh. “Near-Earth asteroid 153958 (2003 AM31) represents 1 of approximately 9,000 whizzing past Earth at any given moment, and we wanted to highlight this one as it’s only 13.7 lunar distances from Earth — similar to near-Earth asteroid LZ1 which zoomed past us unexpectedly mid-June.”

Oldest Impact Crater on Earth Discovered in Greenland

Artistic expression of large meteorite impact
An artistic expression of how a large meteorite impact into the sea might have looked in the first second of the impacting. We do not know if the area that was hit was actually covered by water or if there was just a sea nearby. Source: Carsten Egestal Thuesen, GEUS

With shifting continents, rain, and wind, finding traces of ancient impact craters on Earth has been, literally, astronomically low. Now, an international team of scientists say they have found a massive impact crater in Greenland a billion years older than other known asteroid impact on Earth.

Scientists found the remains of the giant 100-kilometer (62 mile) wide crater near the Maniitsoq region of West Greenland and they believe it’s three billion years old. The largest and previously oldest known crater is the 300 kilometer-wide Vredefort crater in South Africa. Tipped on its side, the edges of the Maniitsoq crater would extend from the surface of the Earth to the edge of space.


“This single discovery means that we can study the effects of cratering on the Earth nearly a billion years further back in time than was possible before,” according to Dr. Iain McDonald of the School of Earth and Ocean Sciences at Cardiff University, who was part of the team.

Finding the crater wasn’t an easy task. Today, the Moon still shows marks of the massive bombardment that took place between three and four billion years ago. The early Earth, with its greater gravitational attraction, would have experienced even more collisions. But the land around Maniitsoq has been eroded over the eons to expose crust that originally was 25 kilometers (16 miles) below the surface. Effects of the immense shockwave produced on impact penetrated deep into the crust and remain visible.

Evidence at that depth had never been observed before, says McDonald. “The process was rather like a Sherlock Holmes story,” said McDonald. “We eliminated the impossible in terms of any conventional terrestrial processes, and were left with a giant impact as the only explanation for all of the facts.”

Only about 180 impact craters have been discovered on Earth. Around 30 percent of them contain important natural resources, including nickel, gold, oil and natural gas. It was during an exploration of natural resources that evidence for the crater was discovered. “It has taken us nearly three years to convince our peers in the scientific community,” said McDonald. “But the mining industry was far more receptive. A Canadian exploration company has been using the impact model to explore for deposits of nickel and platinum metals at Maniitsoq since the autumn of 2011.”

The international team, led by Adam Garde, a senior research scientist at the Geological Survey of Denmark and Greenland, or GEUS, contains members from Cardiff, Lund University in Sweden, and the Institute of Planetary Science in Moscow. Their work was recently published in the jounal Earth and Planetary Science Letters.

Image caption: An artistic expression of how a large meteorite impact into the sea might have looked in the first second of the impacting. We do not know if the area that was hit was actually covered by water or if there was just a sea nearby. Source: Carsten Egestal Thuesen, GEUS

Map caption: Black circle on map shows the location of the meteorite impact structure near the town Maniitsoq in Greenland.

Read more about the Maniitsoq structure.

Weekly Space Hangout – June 21, 2012

In this edition of the Weekly Space Hangout, we welcome a new participant: Mike Wall, senior writer at Space.com. We were also joined by Alan Boyle from MSNBC’s Cosmic Log, Ian O’Neill from Discovery Space, and Amy Shira Teitel from Vintage Space.

This week we talked about using black holes as particle detectors, the recent launch of a female Chinese astronaut, the historical echoes of China and the Soviet Union launching women into space, and the newly announced asteroid telescope by the B612 Foundation.

We record the Weekly Space Hangout on Google+ every Thursday at 10 am Pacific / 1 pm Eastern. Circle Fraser on Google+, to see the show when it’s happening live.

Recent Earth-Passing Asteroid is Much Bigger Than Originally Estimated

An asteroid that recently passed by Earth is about twice as large as originally estimated, and it would have had serious global consequences if it had impacted Earth. Asteroid 2012 LZ1 was only discovered on June 10, 2012 by Rob McNaught at the Siding Spring Observatory in Australia. This Near Earth Object was thought to be fairly large, 502 meters (1,650 feet) wide, and quite bright. But astronomers using the planetary radar system at Arecibo Observatory were able to better determine the asteroid’s size, rotation rate and shape and found it to be about 1 kilometer (0.6 miles) wide and actually quite dark.

Scientists consider a kilometer-wide asteroid is at the size threshold that could set off an extinction-level event if it were to hit Earth.

“This object turned out to be quite a bit bigger than we expected, said Dr. Ellen Howell from Arecibo, “which shows how important radar observations can be, because we’re still learning a lot about the population of asteroids.”

2012 LZ1 sneaked by our planet at about 5.3 million km (3.35 million) miles away, or about 14 times the distance between Earth and the Moon on June 14, and it won’t be back in Earth’s vicinity again until June 12th, 2053, and then will be about 3 times as distant.
The Arecibo astronomers have determined it won’t be a threat to Earth for at least 750 years.

“The sensitivity of our radar has permitted us to measure this asteroid’s properties and determine that it will not impact the Earth at least in the next 750 years,” said Dr. Mike Nolan, Director of Planetary Radar Sciences at the Arecibo Observatory.

Several amateur astronomers were able to image 2012 LZ1, and the original thinking was that it was very bright. Instead, the new size determination suggests that 2012 LZ1 must be quite dark, reflecting only 2-4% of the light that hits it.

This is another reminder that we don’t know everything about all the potential asteroid threats that are out there, and more searches need to be done to find and track as many of the near Earth asteroid population as possible. Asteroid 2012 LZ1 has been classified as a Potentially Hazardous Asteroid, which are asteroids larger than approximately 100 meters that can come closer to our planet than 0.05 AU (7.4 million km, 4.65 million miles). As of now, none of the known PHAs is on a collision course with our planet, but both amateur and professional astronomers are finding new ones all the time, sometimes with just a few hours’ notice of a close approach.

Lead image caption: Asteroid 2012 LZ1 as seen by the Haleakala-Faulkes Telescope North on June 13, 2012. Credit: Nick Howes, Ernesto Guido & Giovanni Sostero.

Source: Arecibo Observatory via SpaceRef.