Radar image of asteroid 2006 DP14. Click for larger. Credit: NASA et al.
I must confess I’ve never really considered this before and the way the press release is worded leaves me with the question: are these “contact binaries” actually two separate asteroids or are they just sort of stuck together by whatever (like gravitationally bound, impact fused etc)?
The NASA press release:
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, Calif., on the night of Feb. 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 Feb. 11 between 9:03 a.m. and 11:27 p.m. PST (12:03 a.m. to 2:27 a.m. EST on Feb. 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 Feb. 10, at a distance of about 1.5 million miles (2.4 million kilometers).
A solar flare photographed in different wavelengths of light by the SDO. Image Credit: NASA/SDO
We had a bit of an aurora last night, it was nice to see. The Boulder K index was 6 for a while.
This was all thanks to an X-class flare which was imaged by the Solar Dynamics Observatory (SDO). The flare took place at 12:25 UTC (24 February, 19:25 EST).
The SDO took images in different wavelengths and you can see the result. Larger versions of the image can be found at this NASA page.
Watch the video!
And if you missed the aurora don’t worry more will happen, I saw this one by accident myself, thanks to the dog. LOL.
An image of the flash resulting from the impact of a large meteorite on the lunar surface on 11 September 2013, obtained with the MIDAS observatory. Credit: J. Madiedo / MIDAS
A meteorite with about the mass of a small car impacted the moon last September and it was seen by Spanish astronomers. I don’t often mention Spanish astronomers, more the pity and bad on me. Spain has some of the best observers and astronomers as there are anywhere.
In this case on 11 September 2013, Prof. Jose M. Madiedo was operating two telescopes in the south of Spain that were searching for these impact events. At 2007 UTC he witnessed an unusually long and bright flash in Mare Nubium, an ancient lava-filled basin with a darker appearance than its surroundings.
We are hearing about this now because the scientists involved published their description of the event in the journal Monthly Notices of the Royal Astronomical Society. By the way, video links are included below the fold.
The Spanish telescopes are part of the Moon Impacts Detection and Analysis System (MIDAS) system that monitors the lunar surface. This project is being undertaken by Prof. Jose Maria Madiedo, from the University of Huelva (UHU), and by Dr. Jose L. Ortiz, from the Institute of Astrophysics of Andalusia (IAA-CSIC) and continues a pioneering program that detected sporadic lunar impact flashes for the first time.
ESA’s Gaia satellite as seen with the Very Large Telescope Survey Telescope at the European Southern Observatory in Chile. Credit: ESO / ESA
The Gaia satellite is 1.5 million km away and is orbiting a spot in space known as L2. The spot, L2 is a Lagrange point, think of it as a gravity balance point and makes a nice parking spot. ESA has a more in depth explanation of Lagrange points..
ESA can actually keep tabs on Gaia visually. I think this is just amazing. Using the Very Large Telescope at the European Southern Observatory in Chile Gaia actually can be seen. It’s a very small satellite very far away, over a million times fainter than can be see with the human eye.
From the ESA caption:
To measure Gaia’s position in the sky, a network of small and medium telescopes are monitoring the spacecraft on a daily basis. This information is being fed into the orbit reconstruction being performed at ESA’s Space Operations Centre, yielding an accuracy of 150 m on Gaia’s position and of 2.5 mm/s on its motion.
These two images, taken about 6.5 minutes apart on 23 January, are the result of a close collaboration between ESA and the European Southern Observatory to observe Gaia.
Read the full ESA caption here.