Asteroid 2014 HQ124

NASA scientists used Earth-based radar to produce these sharp views -- an image montage and a movie sequence -- of the asteroid designated "2014 HQ124" on June 8, 2014.

2014 HQ124 is what scientists call a "contact binary": an asteroid that consists of two lobes that are in contact and that could have once been separate objects. About one in six asteroids in the near-Earth population has this type of elongated, "peanut" shape.

The asteroid is about 1,300 feet (400 meters) long and about half as wide. The radar images reveal a wealth of interesting features, including a large depression or concavity on the larger lobe as well as two blocky, sharp-edged features at the bottom on the radar echo. Scientists suspect that some of the bright features that persist from frame to frame could be surface boulders.

The 21 radar images were taken over a span of four hours. During that interval, the asteroid rotated a few degrees per frame, suggesting its rotation period is slightly less than 24 hours.

At its closest approach to Earth on June 8, the asteroid came within 776,000 miles (1.25 million kilometers), or slightly more than three times the distance to the moon. Scientists began radar observations of 2014 HQ124 shortly after the closest approach, when the asteroid was between about 864,000 miles (1.39 million kilometers) and 902,000 miles (1.45 million kilometers) from Earth.

The new views show features as small as about 12 feet (3.75 meters) wide. This is the highest resolution currently possible using scientific radar antennas to produce images. Such sharp views were made possible for this asteroid by linking together two giant radio telescopes to enhance their capabilities.

To obtain the new views, researchers paired the 230-foot (70-meter) Deep Space Network antenna at Goldstone, California, with two other radio telescopes, one at a time. Using this technique, the Goldstone antenna beams a radar signal at an asteroid and the other antenna receives the reflections. The technique dramatically improves the amount of detail that can be seen in radar images.

To image 2014 HQ124, the researchers first paired the large Goldstone antenna with the 1000-foot (305-meter) Arecibo radio telescope in Puerto Rico. They later paired the large Goldstone dish with a smaller companion, a 112-foot (34-meter) antenna, located about 20 miles (32 kilometers) away.

The first five images in the sequence -- the top row in the montage -- represent the data collected by Arecibo, and demonstrate that these data are 30 times brighter than what Goldstone can produce observing on its own. There is a gap of about 35 minutes between the first and second rows in the montage, or between the fifth and sixth frames in the video. The gap represents the time needed to switch from receiving at Arecibo to receiving at the smaller Goldstone station.

Each image in the montage and movie represents 10 minutes of data. Each frame has the same orientation, delay-Doppler dimensions and resolution (3.75 meters by 0.0125 Hertz).

For asteroids, as well as comets, radar is a powerful tool for studying the objects' size, shape, rotation, surface features and orbits. Radar measurements of asteroid distances and velocities enable researchers to compute orbits much further into the future than if radar observations were not available.

Image credit: NASA/JPL-Caltech/Arecibo Observatory/USRA/NSF

Note: For more information, see Giant Telescopes Pair Up to Image Near-Earth Asteroid.

Asteroid 2006 DP14

This image is one frame from a collage of radar images taken on February 11, 2014, of near-Earth asteroid 2006 DP 14, which is about 1,300 feet (400 meters) long. The imaging used the 230-foot (70-meter) Deep Space Network antenna at Goldstone, California, while the asteroid was about 11 times farther from Earth than the moon is.

A collage of radar images of near-Earth asteroid 2006 DP14 was generated by NASA scientists using the 230-foot (70-meter) Deep Space Network antenna at Goldstone, California, on the night of February 11, 2014.

Delay-Doppler radar imaging revealed that the asteroid is about 1,300 feet (400 meters) long, 660 feet (200 meters) wide, and shaped somewhat like a big peanut. The asteroid's period of rotation is about six hours. The asteroid is of a type known as a "contact binary" because it has two large lobes on either end that appear to be in contact. Previous radar data from Goldstone and the Arecibo Observatory in Puerto Rico has shown that at least 10 percent of near-Earth asteroids larger than about 650 feet (200 meters) have contact binary shapes like that of 2006 DP14. The data were obtained over an interval of 2.5 hours as the asteroid completed about half a revolution. The resolution is about 60 feet (19 meters) per pixel.

The data were obtained on February 11 between 9:03 a.m. and 11:27 p.m. PST (12:03 a.m. to 2:27 a.m. EST on February 12). At the time of the observations, the asteroid's distance was about 2.6 million miles (4.2 million kilometers) from Earth. That is about 11 times the average distance between Earth and its moon. The asteroid's closest approach to Earth occurred on February 10, at a distance of about 1.5 million miles (2.4 million kilometers).

Radar is a powerful technique for studying an asteroid's size, shape, rotation state, surface features and surface roughness, and for improving the calculation of asteroid orbits. Radar measurements of asteroid distances and velocities often enable computation of asteroid orbits much further into the future than if radar observations weren't available.

NASA places a high priority on tracking asteroids and protecting our home planet from them. In fact, the United States has the most robust and productive survey and detection program for discovering near-Earth objects. To date, U.S. assets have discovered more than 98 percent of the known near-Earth objects.

Image credit: NASA/JPL-Caltech/GSSR

Radar Map of Venus

This map of the surface of Venus was created from observations accumulated during more than a decade of radar imaging of the planet. Observations made by NASA's Magellan spacecraft between 1990 and 1994 form the base of the image, with gaps in the data filled in by the Arecibo Observatory, which is based in Puerto Rico. The image is color-coded to show elevation, using information gathered by the Magellan radar altimeter, with additional data provided by the Soviet Venera spacecraft and NASA’s Pioneer Venus missions.

Radar images of Venus have revealed geological structures on the planet, such as steep-sided domes and rugged highland terrain, which geologists think could feature mineral-rich materials, such as felsic rocks.

The discovery of felsic rocks on Venus would add support to the idea that the planet was once more Earth-like, as most of these materials on Earth formed in a water environment. However, other processes that don’t require the presence of water may also produce felsic rocks.

Map credit: NASA/JPL/USGS

Note: This particular view of Venus is centered on 270° East. For more information about this story, see Venus Express Unearths New Clues to the Planet's Geological History