NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) spacecraft has spotted a never-before-seen asteroid — its first such discovery since coming out of hibernation last year.
NEOWISE originally was called the Wide-field Infrared Survey Explorer (WISE), which had made the most comprehensive survey to date of asteroids and comets. The spacecraft was shut down in 2011 after its primary mission was completed. But in September 2013, it was reactivated, renamed and given a new mission, which is to assist NASA’s efforts to identify the population of potentially hazardous near-Earth objects (NEOs). NEOWISE also can assist in characterizing previously detected asteroids that could be considered potential targets for future exploration missions
NEOWISE’s first discovery of its renewed mission came on Dec. 29 — a near-Earth asteroid designated 2013 YP139. The mission’s sophisticated software picked out the moving object against a background of stationary stars. As NEOWISE circled Earth scanning the sky, it observed the asteroid several times over half a day before the object moved beyond its view. Researchers at the University of Arizona used the Spacewatch telescope at the Kitt Peak National Observatory southwest of Tucson to confirm the discovery. Peter Birtwhistle, an amateur astronomer at the Great Shefford Observatory in West Berkshire, England, also contributed follow-up observations. NASA expects 2013 YP139 will be the first of hundreds of asteroid discoveries for NEOWISE.
Using the Gemini North telescope on Mauna Kea, Hawai‘i a team of astronomers from the University of Hawaii’s Institute for Astronomy (IfA) have confirmed that the chance of asteroid 2011 AG5 impacting Earth in 2040 is no longer a significant risk – prompting a collective sigh-of-relief. Previously, scientists estimated that the risk of this 140-meter-diameter (about the length of two American football fields) asteroid colliding with the Earth was as high as one in 500.
If this object were to collide with the Earth it would have released about 100 megatons of energy, several thousand times more powerful than the atomic bombs that ended World-War II. Statistically, a body of this size could impact the Earth on average every 10,000 years.
To deal with potentially hazardous Near Earth Objects (NEOs) that could strike the Earth, there is need to establish an effective international communications strategy – but doing so is a daunting task, one that demands effective use of mass communication tools.
The report and its findings are being presented this week to the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) and its Action Team-14 on NEOs during the 55th session of the UN COPUOS being held in Vienna, Austria.
Earth usually has more than one moon, according to a team of astronomers from the University of Helsinki, the Paris Observatory and the University of Hawaii at Manoa.
Our 2,000-mile-diameter Moon, so beloved by poets, artists and romantics, has been orbiting Earth for over 4 billion years. Its much smaller cousins, dubbed “minimoons,” are thought to be only a few feet across and to usually orbit our planet for less than a year before resuming their previous lives as asteroids orbiting the Sun.
Mikael Granvik (formerly at UH Manoa and now at Helsinki), Jeremie Vaubaillon (Paris Observatory) and Robert Jedicke (UH Manoa) calculated the probability that at any given time Earth has more than one moon. They used a supercomputer to simulate the passage of 10 million asteroids past Earth. They then tracked the trajectories of the 18,000 objects that were captured by Earth’s gravity.
They concluded that at any given time there should be at least one asteroid with a diameter of at least one meter orbiting Earth. Of course, there may also be many smaller objects orbiting Earth, too.
Newly-discovered asteroid 2012 BX34 is flying past Earth today only 77,000 km (0.2 lunar distances) away. There is no danger of a collision with the 14-meter wide space rock.
X2 Solar Flare
Departing sunspot 1402 unleashed an X2-class solar flare today, Jan. 27th, at 18:37 UT. Sunspot 1402 is rotating onto the far side of the sun, so the blast site was not facing Earth. Nevertheless, energetic protons accelerated by the blast are now surrounding our planet, and an intensifying S1-class radiation storm is in progress.
An asteroid impact with the earth can really ruin your day: just consider the dinosaurs. Most asteroids, also known as minor planets, orbit the sun beyond the planet Mars and present no danger, but there is a class of asteroids whose orbits cross the orbit of the earth. If one of these asteroids and the earth are at the same point in their orbits at the same time, a collision could occur. Called Near Earth Objects (NEOs), astronomers are interested in discovering as many of these as possible, and then tracking them in order to compute more accurate orbits. In this way, if a potential future collision were to be identified many years in advance, space probes could carry out steps to tweak the path of the NEO and deflect the collision. A program to track NEOs is being carried out at NOAO by Mark Trueblood with Robert Crawford (Rincon Ranch Observatory) and Larry Lebofsky (Planetary Science Institute). And last summer, a Beloit College student, Morgan Rehnberg, has developed a computer program (PhAst), available via the web, to help with this effort.
Asteroids move quickly across the sky, so in order to recover and track them, fast and accurate data reduction and analysis is essential. Unlike most of the data that astronomers work with, tracking a fast moving asteroid requires that the observer view multiple digital images obtained at the telescope by blinking between them, almost like a movie. In addition, accurate coordinates locating the NEO in the sky need to be computed. (Termed right ascension and declination, these are similar in concept to the latitude and longitude of a position on earth.) While there are many software packages that amateur and professional astronomers use (Maxim DL, Astrometrica) none did exactly what the group required. Seeing the need for better software but not having the time to devote to the task of writing it, Trueblood saw this as an ideal project for a summer student.
Full Story: http://www.noao.edu/news/2011/pr1107.php
NASA Scientists working with the 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, Calif., have released a second, longer, and more refined, movie clip of asteroid 2005 YU55. The images were generated from data collected at Goldstone on Nov. 7, 2011, between 11:24 a.m. and 1:35 p.m. PST (2:24 p.m. and 4:35 p.m. EST).
The movie clip can be found at: http://1.usa.gov/YU55 .
Each of the 28 frames required 20 minutes of data collection by the Goldstone radar. At the time of the observations, 2005 YU55 was approximately 860,000 miles (1.4 million kilometers) from Earth. The resolution is about 13 feet (4 meters) per pixel. 2005 YU55 takes approximately 18 hours to complete one rotation, so the rotation in the movie appears much more rapid than the actual asteroid rotation speed.
The Goldstone observations utilized a new system to obtain images with a resolution of 4 meters, which is five times finer than the highest resolution previously possible at Goldstone.