Posted on by Bob King

2014 JO25 Flies By Earth — See It Tonight

Credit; NASA/JPL-Caltech/GSSR
This composite of 30 images of asteroid 2014 JO25 was generated with radar data collected using NASA’s Goldstone Solar System Radar in California’s Mojave Desert on Tuesday April 18. Credit: NASA/JPL-Caltech/GSSR

Asteroid 2014 JO25, discovered in 2014 by the Catalina Sky Survey in Arizona, was in the spotlight today (April 19) when it flew by Earth at just four times the distance of the Moon. Today’s encounter is the closest the object has come to the Earth in 400 years and will be its closest approach for at least the next 500 years.

Lots of asteroids zip by our planet, and new ones are discovered every week. What makes 2014 JO25 different it’s one of nearly 1,800 PHAs (Potentially Hazardous Asteroids) that are big enough and occasionally pass close enough to Earth to be of concern. PHAs have diameters of at least 100-150 meters (330-490 feet) and pass less than 0.05 a.u (7.5 million km / 4.6 million miles) from our planet. Good thing for earthlings, no known PHA is predicted to impact Earth for at least the next 100 years.

Most of these Earth-approachers are on the small side, only a few to a few dozen meters (yards) across. 2014 JO25 was originally estimated at ~2,000 feet wide, but thanks to radar observations made the past couple days, we now know it’s nearly twice that size. Radar images of asteroid were made early this morning with NASA’s 230-foot (70-meter) radio antenna at Goldstone Deep Space Communications Complex in California. They reveal a peanut-shaped asteroid that rotates about once every 5 hours and show details as small as 25 feet.


NASA radar images and animation of asteroid 2015 JO25

The larger of the two lobes is about 2,000 feet (620 meters) across, making the total length closer to 4,000 feet. That’s similar in size (though not as long) as the Rock of Gibraltar that stands at the southwestern tip of Europe at the tip of the Iberian Peninsula.

“The asteroid has a contact binary structure — two lobes connected by a neck-like region,” said Shantanu Naidu, a scientist from NASA’s Jet Propulsion Laboratory in Pasadena, California, who led the Goldstone observations. “The images show flat facets, concavities and angular topography.” Contact binaries form when two separate asteroids come close enough together to touch and meld as one.

The Goldstone dish dish, based in the Mojave Desert near Barstow, Cal. is used for radar mapping of planets, comets, asteroids and the Moon. Credit: NASA

Radar observations of the asteroid have also been underway at the National Science Foundation’s Arecibo Observatory in Puerto Rico with more observations coming today through the 21st which may show even finer details. The technique of pinging asteroids with radio waves and eking out information based on the returning echoes has been used to observe hundreds of asteroids.

When these relics from the early solar system pass relatively close to Earth, astronomers can glean their sizes, shapes, rotation, surface features, and roughness, as well as determine their orbits with precision.

Because of 2014 JO25’s relatively large size and proximity, it’s bright enough to spot in a small telescope this evening. It will shine around magnitude +10.9 from North America tonight as it travels south-southwest across the dim constellation Coma Berenices behind the tail of Leo the Lion. A good map and 3-inch or larger telescope should show it.

Use the maps at this link to help you find and track the asteroid tonight. The key to spotting it is to allow time to identify and get familiar with the star field the asteroid will pass through 10 to 15 minutes in advance — then lay in wait for the moving object. Don’t be surprised if 2014 JO25 deviates a little from the predicted path depending on your location and late changes to its orbit, so keep watch not only on the path but around it, too. Good luck!

Posted on by Matt Williams

NASA Invests In Radical Game-Changing Concepts For Exploration

Artist's concept of some of the Phase I winners of the 2016 NIAC program. Credit: NASA

Every year, the NASA Innovative Advanced Concepts (NIAC) program puts out the call to the general public, hoping to find better or entirely new aerospace architectures, systems, or mission ideas. As part of the Space Technology Mission Directorate, this program has been in operation since 1998, serving as a high-level entry point to entrepreneurs, innovators and researchers who want to contribute to human space exploration.

This year, thirteen concepts were chosen for Phase I of the NIAC program, ranging from reprogrammed microorganisms for Mars, a two-dimensional spacecraft that could de-orbit space debris, an analog rover for extreme environments, a robot that turn asteroids into spacecraft, and a next-generation exoplanet hunter. These proposals were awarded $100,000 each for a nine month period to assess the feasibility of their concept.

Continue reading “NASA Invests In Radical Game-Changing Concepts For Exploration”

Posted on by Bob King

Asteroid 2014 KH39 Zips Just 1.1 LD from Earth – Watch it LIVE June 3

Near Earth asteroid 2014 KH39, discovered on May 24, 2014, is the faint 'star' in the crosshairs in this photo made on May 31. The telescope tracked the asteroid, so the stars are trailed. The streak is a satellite. Credit: Gianluca Masi

Got any plans Tuesday? Good. Keep them but know this. That day around 3 p.m. CDT (20:00 UT) asteroid 2014 KH39 will silently zip by Earth at a distance of just 272,460 miles (438,480 km) or 1.14 LDs (lunar distance). Close as flybys go but not quite a record breaker. The hefty space rock will buzz across the constellation Cepheus at nearly 25,000 mph (11 km/sec) near the Little Dipper at the time.

Observers in central Europe and Africa will have  dark skies for the event, however at magnitude +17 the asteroid will be too faint to spot in amateur telescopes. No worries. The Virtual Telescope Project, run by astrophysicist Gianluca Masi, will be up and running with real-time images and live commentary during the flyby. The webcast begins at 2:45 p.m. CDT June 3.

2014 KH39 was discovered on May 24 by Richard Kowalski of the Catalina Sky Survey. (Kowalski is the same astronomer who discovered asteroid 2008 TC3, the small asteroid that impacted in Sudan in 2008). Further observations by the CSS and additional telescopes like Pan-STARRS 1 in Hawaii nailed down its orbit as an Earth-approacher with an approximate size of 72 feet (22 meters). That’s a tad larger than the 65-foot Chelyabinsk asteroid that exploded into thousands of small stony meteorites over Russia in Feb. 2013.

Diagram showing the orbit of 2014 KH39. Yellow shows the portion of its orbit above the plane of Earth’s orbit (grey disk); blue is below the plane. When farthest, the asteroid travels beyond Mars into the asteroid belt. It passes closest to Earth around 3 p.m. CDT June 3. Credit: IAU Minor Planet Center
Diagram showing the orbit of 2014 KH39. Yellow shows the portion of its orbit above the plane of Earth’s orbit (grey disk); blue is below the plane. When farthest, the asteroid travels beyond Mars into the asteroid belt. It passes closest to Earth around 3 p.m. CDT June 3. Credit: IAU Minor Planet Center

Since this asteroid will safely miss Earth we have nothing to fear from the flyby. I only report it here to point out how common near-Earth asteroids are and how remarkable it is that we can spot them at all. While we’re a long ways from finding and tracking all potentially hazardous asteroids, dedicated sky surveys turn up dozens of close-approaches every year. On the heels of 2014 KH39, the Earth-approaching asteroid 2014 HQ124 will pass 3.3 LDs away 5 days later on June 8. With a diameter estimated at more than 2,100 feet (650-m) it’s expected to become as bright as magnitude +13.7. Southern hemisphere observers might track it with 8-inch and larger telescopes as its speeds across Horologium and Eridanus the morning before closest approach.

The chart shows the cumulative known total of near-Earth asteroids (NEAs) vs. time. The blue area shows all NEAs while the red shows those roughly 1 km and larger. Thanks to many surveys underway as well as help from space probes like the Wide-Field Infrared Explorer (WISE), discovery totals have been ramping up. Credit: NASA
The chart shows the cumulative known total of near-Earth asteroids (NEAs) vs. time. The blue area shows all NEAs while the red shows those roughly 1 km and larger. Thanks to many ground-based surveys underway as well as space probes like the Wide-field Infrared Survey Explorer (WISE), discovery totals have ramped up in recent years. There are probably millions of NEOs smaller than 140 meters waiting to be discovered. Credit: NASA

Perusing the current list of upcoming asteroid approaches, these two will be our closest visitors at least through early August. Near-Earth objects (NEOs) are comets and asteroids whose original orbits have been re-worked by the gravity of the planets – primarily Jupiter – into new orbits that allow them to approach relatively close to Earth. The ones we’re most concerned about are a subset called Potentially Hazardous Asteroids or PHAs, defined as objects that approach within 4.65 million miles (7.48 million km) of Earth and span 500 feet (150-m) across or larger. The key word here is ‘potential’. PHAs won’t necessarily hit the Earth – they only have the potential to do so over the vastness of time. On the bright side, PHAs make excellent targets for sampling missions.

Most near-Earth asteroids fall into three classes named after the first asteroid discovered in that class. Apollo and Aten asteroids cross Earth's orbit; Amors orbit just beyond Earth but cross Mars' orbit. Credit: Wikipedia
Most near-Earth asteroids fall into three classes named after the first asteroid discovered in that class. Apollo and Aten asteroids cross Earth’s orbit; Amors orbit just beyond Earth but cross Mars’ orbit. Credit: Wikipedia

As of May 30, 2014, 11,107 near-Earth objects have been discovered with 860 having a diameter of 1 km or larger. 1,481 of them have been further classified as potentially hazardous. NASA’s Near-Earth Object Program estimates that over 90% of NEOs larger than 1 km (the most potentially lethal to the planet) have been discovered and they’re now working to find 90% of those larger than 459 feet (140 meters) across. Little by little we’re getting to better know the neighborhood.

The probability that either 2014 KH39 and 2014 HQ124 will hit Earth on this round is zero. Nor do we know of any asteroid in the near future on a collision course with the planet. Enjoy the day.

Posted on by Jason Major

Say Hello to Asteroid 2007 PA8

Radar images of asteroid 2007 PA8 acquired on October 28, 29 and 30. (NASA/JPL-Caltech/Gemini)

Take a good look at asteroid 2007 PA8 — over the past week it was making its closest pass of Earth for the next 200 years… and NASA’s 230-foot (70-meter) -wide Deep Space Network antenna at Goldstone, California snapped its picture as it went by.

All right, maybe no “pictures” were “snapped”… 2007 PA8 is a small, dark body that only came within four million miles (6.5 million kilometers) today, Nov. 5 (0.043 AU, or 17 times the distance from Earth to the Moon). But the radar capabilities of the Deep Space Network antenna in California’s Mojave Desert can bounce radar off even the darkest asteroids, obtaining data that can be used to create a detailed portrait.

In the image above, a composite of radar data acquired on October 28, 29 and 30, we can see the irregular shape of 2007 PA8 as it rotates slowly — only once every 3-4 days. The perspective is looking “down” at the 1-mile (1.6-km) -wide asteroid’s north pole, showing ridges and perhaps even some craters.

Although classified as a Potentially Hazardous Asteroid (PHA) by the IAU’s Minor Planet Center the trajectory of 2007 PA8 is well understood. It is not expected to pose any impact threat to Earth in the near or foreseeable future.

2007 PA8 was discovered by LINEAR on August 9, 2007.

Read more about asteroid radar imaging here, and find out more about asteroids at JPL’s Asteroid Watch site here.

Get more information on the known properties of 2007 PA8 here.

Source: NASA Solar System Exploration. Image credits: NASA/JPL-Caltech/Gemini