Asteroid 2014 JO25 was imaged by radar from NASA's Goldstone Deep Space Communications Complex in California one day before its closest approach to Earth. A grid composed of 30 images shows the two-lobed asteroid in different rotations. The space rock passed Earth on April 19, 2017, at a distance of 1.1 million miles (1.8 million kilometers).
Asteroid 2014 JO25 was imaged by radar from NASA's Goldstone Deep Space Communications Complex in California one day before its closest approach to Earth. A grid composed of 30 images shows the two-lobed asteroid in different rotations. The space rock passed Earth on April 19, 2017, at a distance of 1.1 million miles (1.8 million kilometers).
NASA/JPL-Caltech/Goldstone Solar System Radar
A graphic shows asteroid 2014 JO25 as it is projected to fly safely past Earth on April 19, 2017, at a distance of about 1.1 million miles or about 4.6 times the distance from Earth to the moon.
A graphic shows asteroid 2014 JO25 as it is projected to fly safely past Earth on April 19, 2017, at a distance of about 1.1 million miles or about 4.6 times the distance from Earth to the moon.
NASA
This graphic illustrates asteroid 2016 HO3 orbiting Earth as the pair go around the sun together. The asteroid was first spotted on April 27, 2016, by the Pan-STARRS 1 asteroid survey telescope on Haleakala, Hawaii.
This graphic illustrates asteroid 2016 HO3 orbiting Earth as the pair go around the sun together. The asteroid was first spotted on April 27, 2016, by the Pan-STARRS 1 asteroid survey telescope on Haleakala, Hawaii.
NASA/JPL-Caltech
This graphic shows the track for asteroid 2004 BL86, which flew about 745,000 miles from Earth on January 26, 2015. That's about three times as far away as the moon.
All about asteroids —
This graphic shows the track for asteroid 2004 BL86, which flew about 745,000 miles from Earth on January 26, 2015. That's about three times as far away as the moon.
NASA/JPL
This graphic shows the path Asteroid 2014 RC took as it passed Earth on September 7, 2015. The space rock came within one-tenth the distance from Earth to the moon.
This graphic shows the path Asteroid 2014 RC took as it passed Earth on September 7, 2015. The space rock came within one-tenth the distance from Earth to the moon.
NASA/JPL
NASA scientists used Earth-based radar to produce these sharp views of the asteroid designated<a href="index.php?page=&url=http%3A%2F%2Fwww.nasa.gov%2Fjpl%2Fasteroid%2Fgiant-telescopes-pair-up-to-image-near-earth-asteroid%2Findex.html%23.U5nrgii4SEK" target="_blank" target="_blank"> "2014 HQ124"</a> on June 8, 2014. NASA called the images "most detailed radar images of a near-Earth asteroid ever obtained."
NASA scientists used Earth-based radar to produce these sharp views of the asteroid designated "2014 HQ124" on June 8, 2014. NASA called the images "most detailed radar images of a near-Earth asteroid ever obtained."
NASA/JPL-Caltech/Arecibo Observatory/USRA/NSF
The Hubble Space Telescope snapped a series of images on September 10, 2013, revealing a never-before-seen sight: An asteroid that appeared to have <a href="index.php?page=&url=http%3A%2F%2Fwww.nasa.gov%2Fpress%2F2013%2Fnovember%2Fnasas-hubble-sees-asteroid-spouting-six-comet-like-tails%2F%23.VAilBPmwLYg" target="_blank" target="_blank">six comet-like tails</a>.
The Hubble Space Telescope snapped a series of images on September 10, 2013, revealing a never-before-seen sight: An asteroid that appeared to have six comet-like tails.
D. Jewitt/ESA/NASA
A diagram shows the orbit of an asteroid named 2013 TV135 (in blue), which made headlines in September 2013 when it passed close by Earth. The probability of it striking Earth one day stands at 1 in 63,000, and even those odds are fading fast as scientists find out more about the asteroid. It will most likely swing past our planet again in 2032, according to NASA.
A diagram shows the orbit of an asteroid named 2013 TV135 (in blue), which made headlines in September 2013 when it passed close by Earth. The probability of it striking Earth one day stands at 1 in 63,000, and even those odds are fading fast as scientists find out more about the asteroid. It will most likely swing past our planet again in 2032, according to NASA.
NASA/Jet Propulsion Laboratory-Caltech
Asteroid 2012 DA14 made a record-close pass -- 17,100 miles -- by Earth on February 15, 2013. Most asteroids are made of rocks, but some are metal. They orbit mostly between Jupiter and Mars in the main asteroid belt. Scientists estimate there are tens of thousands of asteroids and when they get close to our planet, they are called near-Earth objects.
Asteroid 2012 DA14 made a record-close pass -- 17,100 miles -- by Earth on February 15, 2013. Most asteroids are made of rocks, but some are metal. They orbit mostly between Jupiter and Mars in the main asteroid belt. Scientists estimate there are tens of thousands of asteroids and when they get close to our planet, they are called near-Earth objects.
nasa
Another asteroid, Apophis, got a lot of attention from space scientists and the media when initial calculations indicated a small chance it could hit Earth in 2029 or 2036. NASA scientists have since ruled out an impact, but on April 13, 2029, Apophis, which is about the size of 3½ football fields, will make a close visit -- flying about 19,400 miles (31,300 kilometers) above Earth's surface. The images above were taken by the European Space Agency's Herschel Space Observatory in January 2013.
Another asteroid, Apophis, got a lot of attention from space scientists and the media when initial calculations indicated a small chance it could hit Earth in 2029 or 2036. NASA scientists have since ruled out an impact, but on April 13, 2029, Apophis, which is about the size of 3½ football fields, will make a close visit -- flying about 19,400 miles (31,300 kilometers) above Earth's surface. The images above were taken by the European Space Agency's Herschel Space Observatory in January 2013.
ESA/Herschel/PACS/MACH-11/MPE/ESAC
If you really want to know about asteroids, you need to see one up close. NASA did just that. A spacecraft called NEAR-Shoemaker, named in honor of planetary scientist Gene Shoemaker, was the first probe to touch down on an asteroid, landing on the asteroid Eros on February 12, 2001. This image was taken on February 14, 2000, just after the probe began orbiting Eros.
If you really want to know about asteroids, you need to see one up close. NASA did just that. A spacecraft called NEAR-Shoemaker, named in honor of planetary scientist Gene Shoemaker, was the first probe to touch down on an asteroid, landing on the asteroid Eros on February 12, 2001. This image was taken on February 14, 2000, just after the probe began orbiting Eros.
NASA
The first asteroid to be identified, 1 Ceres, was discovered January 1, 1801, by Giuseppe Piazzi in Palermo, Sicily. But is Ceres just another asteroid? Observations by NASA's Hubble Space Telescope show that Ceres has a lot in common with planets like Earth. It's almost round and it may have a lot of pure water ice beneath its surface. Ceres is about 606 by 565 miles (975 by 909 kilometers) in size and scientists say it may be more accurate to call it a mini-planet. NASA's Dawn spacecraft is on its way to Ceres to investigate. The spacecraft is 35 million miles (57 million kilometers) from Ceres and 179 million miles (288 million kilometers) from Earth. The photo on the left was taken by Keck Observatory, Mauna Kea, Hawaii. The image on the right was taken by the Hubble Space Telescope.
The first asteroid to be identified, 1 Ceres, was discovered January 1, 1801, by Giuseppe Piazzi in Palermo, Sicily. But is Ceres just another asteroid? Observations by NASA's Hubble Space Telescope show that Ceres has a lot in common with planets like Earth. It's almost round and it may have a lot of pure water ice beneath its surface. Ceres is about 606 by 565 miles (975 by 909 kilometers) in size and scientists say it may be more accurate to call it a mini-planet. NASA's Dawn spacecraft is on its way to Ceres to investigate. The spacecraft is 35 million miles (57 million kilometers) from Ceres and 179 million miles (288 million kilometers) from Earth. The photo on the left was taken by Keck Observatory, Mauna Kea, Hawaii. The image on the right was taken by the Hubble Space Telescope.
One big space rock got upgraded recently. This image of Vesta was taken by the Dawn spacecraft, which is on its way to Ceres. In 2012, scientists said data from the spacecraft show Vesta is more like a planet than an asteroid and so Vesta is now considered a protoplanet.
One big space rock got upgraded recently. This image of Vesta was taken by the Dawn spacecraft, which is on its way to Ceres. In 2012, scientists said data from the spacecraft show Vesta is more like a planet than an asteroid and so Vesta is now considered a protoplanet.
NASA/JPL-Caltech
The three-mile long (4.8-kilometer) asteroid Toutatis flew about 4.3 million miles (6.9 million kilometers) from Earth on December 12, 2012. NASA scientists used radar images to <a href="index.php?page=&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Dfo38qU00HlQ" target="_blank" target="_blank">make a short movie</a>.
The three-mile long (4.8-kilometer) asteroid Toutatis flew about 4.3 million miles (6.9 million kilometers) from Earth on December 12, 2012. NASA scientists used radar images to make a short movie.
NASA/JPL-Caltec
Asteroids have hit Earth many times. It's hard to get an exact count because erosion has wiped away much of the evidence. The mile-wide Meteor Crater in Arizona, seen above, was created by a small asteroid that hit about 50,000 years ago, NASA says. Other famous impact craters on Earth include Manicouagan in Quebec, Canada; Sudbury in Ontario, Canada; Ries Crater in Germany, and Chicxulub on the Yucatan coast in Mexico.
Asteroids have hit Earth many times. It's hard to get an exact count because erosion has wiped away much of the evidence. The mile-wide Meteor Crater in Arizona, seen above, was created by a small asteroid that hit about 50,000 years ago, NASA says. Other famous impact craters on Earth include Manicouagan in Quebec, Canada; Sudbury in Ontario, Canada; Ries Crater in Germany, and Chicxulub on the Yucatan coast in Mexico.
Smithsonian Scientific Series
NASA scientists say the impact of an asteroid or comet several hundred million years ago created the Aorounga crater in the Sahara Desert of northern Chad. The crater has a diameter of about 10.5 miles (17 kilometers). This image was taken by the Space Shuttle Endeavour in 1994.
NASA scientists say the impact of an asteroid or comet several hundred million years ago created the Aorounga crater in the Sahara Desert of northern Chad. The crater has a diameter of about 10.5 miles (17 kilometers). This image was taken by the Space Shuttle Endeavour in 1994.
nasa
In 1908 in Tunguska, Siberia, scientists theorize an asteroid flattened about 750 square miles (1,200 square kilometers) of forest in and around the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia.
In 1908 in Tunguska, Siberia, scientists theorize an asteroid flattened about 750 square miles (1,200 square kilometers) of forest in and around the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia.
Leonid Kulik Expedition
What else is up there? Is anyone watching? NASA's <a href="index.php?page=&url=http%3A%2F%2Fneo.jpl.nasa.gov%2F" target="_blank" target="_blank">Near-Earth Object Program</a> is trying to track down all asteroids and comets that could threaten Earth. NASA says 9,672 near-Earth objects have been discovered as of February 5, 2013. Of these, 1,374 have been classified as Potentially Hazardous Asteroids, or objects that could one day threaten Earth.
What else is up there? Is anyone watching? NASA's Near-Earth Object Program is trying to track down all asteroids and comets that could threaten Earth. NASA says 9,672 near-Earth objects have been discovered as of February 5, 2013. Of these, 1,374 have been classified as Potentially Hazardous Asteroids, or objects that could one day threaten Earth.
NASA/JPL-Caltech
One of the top asteroid-tracking scientists is Don Yeomans at the Jet Propulsion Laboratory, which is managed by the California Institute of Technology. Yeomans says every day, "Earth is pummeled by more than 100 tons of material that spewed off asteroids and comets." Fortunately, most of the asteroid trash is tiny and it burns up when it hits the atmosphere, creating meteors, or shooting stars. Yeomans says it's very rare for big chunks of space litter to hit Earth's surface. Those chunks are called meteorites.
One of the top asteroid-tracking scientists is Don Yeomans at the Jet Propulsion Laboratory, which is managed by the California Institute of Technology. Yeomans says every day, "Earth is pummeled by more than 100 tons of material that spewed off asteroids and comets." Fortunately, most of the asteroid trash is tiny and it burns up when it hits the atmosphere, creating meteors, or shooting stars. Yeomans says it's very rare for big chunks of space litter to hit Earth's surface. Those chunks are called meteorites.
NASA/JPL-Caltech
Asteroids and comets are popular fodder for Earth-ending science fiction movies. Two of the biggest blockbusters came out in 1998: "Deep Impact" and "Armageddon." (Walt Disney Studios) Others include "Meteorites!" (1998), "Doomsday Rock" (1997), "Asteroid" (1997), "Meteor" (1979), and "A Fire in the Sky" (1978). Can you name others?
Asteroids and comets are popular fodder for Earth-ending science fiction movies. Two of the biggest blockbusters came out in 1998: "Deep Impact" and "Armageddon." (Walt Disney Studios) Others include "Meteorites!" (1998), "Doomsday Rock" (1997), "Asteroid" (1997), "Meteor" (1979), and "A Fire in the Sky" (1978). Can you name others?
courtesy walt disney studios
Asteroid 1998 QE2 is about 3.75 million miles from Earth. The white dot is the moon, or satellite, orbiting the asteroid.
Asteroid 1998 QE2 is about 3.75 million miles from Earth. The white dot is the moon, or satellite, orbiting the asteroid.
NASA/JPL-Caltech/GSSR
All about asteroids

Story highlights

Space probe finds new threats to Earth

Eight of the near-Earth objects found since 2013 are classified as potentially hazardous asteroids

NASA says no big space rocks expected to hit Earth soon, but the small ones can cause trouble too

CNN  — 

When you think of Earth, do you see our bright blue planet floating out in the vast darkness of space? Maybe you imagine the ring of satellites and spacecraft circling the planet.

But do you see the space rocks that could plunge into our planet, causing major destruction?

NASA does.

It’s using a spacecraft called the Near-Earth Object Wide-field Survey Explorer, known as NEOWISE, to track near-Earth objects – asteroids and comets – that could hit our planet.

The NEOWISE space telescope hunts for asteroids and comets.
The NEOWISE space telescope hunts for asteroids and comets.
NASA

NEOWISE has discovered 72 new NEOs since 2013. The tally includes eight objects that are classified as potentially hazardous asteroids – asteroids that could one day approach or hit Earth.

NEOWISE also is helping scientists study space rocks detected earlier by ground-based telescopes. It’s provided new information on a total of 439 NEOs previously detected by those telescopes.

“NEOWISE discovers large, dark, near-Earth objects, complementing our network of ground-based telescopes operating at visible-light wavelengths. On average, these objects are many hundreds of meters across,” Amy Mainzer, NEOWISE principal investigator, said in a news release.

If you combine the number of NEOs spotted by the satellite with the ones identified by ground-based telescopes, a total of 14,246 NEOs had been detected as of this week

So now that you know Earth isn’t sitting out in empty space, you may have some questions.

Are these things going to hit us?

According to NASA’s Near Earth Object Program, no big space rocks are likely to hit us anytime soon.

But keep in mind that smaller space rocks can slip by undetected. Remember Chelyabinsk? There was no warning before a meteor streaked across the sky over Russia on February 15, 2013, and exploded, shattering windows and injuring hundreds of people.

Russian divers find huge suspected meteorite chunk in Chelyabinsk

If we do spot a big asteroid or comet on a collision course with Earth, what can we do?

Maybe we could nuke it, according to NASA. Here’s what the agency’s Asteroid and Comet Watch page says:

“Unless there are a few decades of warning time, hazardous asteroids larger than a few hundred meters in diameter will require enormous energies to deflect or fragment. In the rare case of a large threatening asteroid, nuclear explosions that could push or fragment the object might provide a sufficient response.”

Where do these space rocks come from?

NEOs “have been nudged by the gravitational attraction of the giant planets in our solar system into orbits that allow them to enter Earth’s neighborhood,” according to space scientists.

Besides tracking them, what’s being doing to protect the Earth from NEOs?

NASA says “no government agency, national or international, has been tasked or accepted the responsibility to stop such an asteroid, should one be discovered.”

The space agency is working on a mission to “redirect” an asteroid if it threatens Earth. But that mission won’t be ready to go until the 2020s.

So if you want do something yourself, NASA also has issued an “Asteroid Grand Challenge.” Here’s how it works: Find asteroids, win a prize and possibly save the Earth.