- Gaia satellite sent into space to monitor blind zone between Sun, Earth
- Race intensifies as India launches Mars probes
ASTRONOMERS are not leaving anything to chance as regards possible asteroid impact on Earth by 2032 with the sending into space of a state of the art satellite to monitor the blind zone between the Earth and the sun to warn of incoming asteroids.
According to reports by the Astrophysical Journal and Discovery News, the satellite, Gaia Space Telescope, completed final preparations in Europe last year and will take off from a launch site in French Guiana on November 20, 2013.
There were palpable fears that a recently discovered 1,300-foot-wide (400 meters) asteroid that passed near Earth last month could pay the planet another close visit in 2032. But, the United States National Aeronautic Space Agency (NASA) officials say there is nothing to fear, as the odds that the space rock will hit Earth are extremely slim.
The asteroid, named 2013 TV135, was discovered on October 8, 2013, by astronomers at the Crimean Astrophysical Observatory in Ukraine. Several weeks before it was spotted, however, the huge space rock flew within 4.2 million miles (6.7 million kilometers) of Earth on September 16.
Many details of the asteroid’s orbital path are still unknown, but astronomers estimate it could be back in Earth’s neighborhood in less than 20 years. Still, NASA’s Near-Earth Object Programme Office, which monitors potential threats to the planet, says the probability that 2013 TV135 will impact Earth is only one in 63,000.
Also, the global space race is gathering momentum as India launches Mars probe. The forthcoming launch of a spacecraft to Mars by India is likely to stoke the fires of a burgeoning Asian space race.
The Indian Space Research Organisation (ISRO) is making its final preparations to send an orbiter to the Red Planet.
The principal aim is to test out India’s space technology to see if this emerging space-faring nation is capable of interplanetary missions. The spacecraft will also collect scientific information about the planet’s atmosphere and surface.
The Mangalyaan probe was to have been launched as early as October 28, but rough weather in the Pacific forced officials to delay the launch by a week. The unmanned mission has a launch window lasting until November 19.
If the mission succeeds, ISRO, will become only the fourth space agency, after those in the US, Europe and Russia to have successfully sent a spacecraft to Mars.
Meanwhile, astronomers have previously not been able to spot asteroids in the ‘blind zone’ due to radiation from the sun blocking information.
But now The European Space Agency (ESA) intends to launch the Gaia Space Telescope with its key task being to monitor the area between the Earth and the sun and warn of any impending collisions.
One recent asteroid, which could have been spotted as it travelled through the ‘blind zone’ months before it collided with the Earth, was that of the Russian asteroid of February this year, which caused a spectacular fireball before smashing into Chelyabinsk, 900 miles east of Russia.
Gerry Gilmore, professor of experimental philosophy at Cambridge University’s Institute of Astronomy told the Sunday Times: “Gaia will measure all the asteroids including those between us and the sun which are the really nasty ones because we can’t see them.”
During its five-year-mission the £800 million Gaia will also map the stars with unprecedented precision – giving astronomers the first accurate 3D map of our galaxy and measure distance between the stars.
A spokesman for the ESA said, “during its anticipated lifetime of five years, Gaia will observe each of its 1billion sources about 70 times, resulting in a record of the brightness and position of each source over time.
“Together with the unprecedented accuracy of the astrometric measurements, this will lead to the discovery of planets around other stars, asteroids in our Solar System, icy bodies in the outer Solar System, brown dwarfs, and far-distant supernovae and quasars.
“The list of Gaia’s potential discoveries makes the mission unique in scope and scientific return.”
NASA detects, tracks and characterises asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Programme, commonly called Spaceguard, discovers these objects, characterises a subset of them and identifies their orbits to determine if any could be potentially hazardous to our planet.
Also, the meteor that exploded over the Urals region of Russia in February was a violent reminder that our planet exists in a cosmic shooting gallery. Now, astronomers are focusing on these mysterious small and possibly dangerous objects in the hope of understanding what they are made of and what kind of threat they pose in the future.
Though rare, impact events by objects like the estimated 17-20 meter wide chunk of space rock can cause serious damage to populated regions. The city of Chelyabinsk suffered around 1,200 injuries and millions of dollars’ worth of property damage when the shock wave from the disintegrating meteor hit the ground - what if this happened to another city like New York, London or Moscow?
The fireball that lit up Russian skies on February 15 became the “poster child” for asteroid impact mitigation strategies and drew attention to the underfunded asteroid surveys that are currently our only defense against marauding near-Earth asteroids, or Near Earth Objects (NEOs). It also invigorated new research into the mysterious population of tiny asteroids that may not wipe out countries, but still give populated regions a very bad day.
In new research headed by Amy Mainzer, of NASA’s Jet Propulsion Laboratory in Pasadena, California, a population of NEOs smaller than 100 meters wide that invade our planet’s orbital space were studied using data from NASA’s Wide-field Infrared Survey Explorer (WISE). Taking their cue from small asteroid discoveries made by ground-based visible light surveys, 106 previously unreported infrared observations of small NEOs were analysed.
The new study published in Astrophysical Journal is titled “The Population of Tiny Near-Earth Objects Observed by NEOWISE.”
Inspired by the Chelyabinsk event, Mainzer and her team set out to survey this poorly-understood population of small NEOs. “What can we learn from these objects, particularly the small ones? What is the smallest object that we could see with WISE?” Mainzer asked.
WISE was used to carry out a wide-field survey of asteroids before the mission was put into hibernation in February 2011- a survey known as NEOWISE, of which Mainzer is principal investigator. The software used to analyse the NEOWISE data was set up to confirm the detection of asteroids that were observed five or more times, in order to avoid registering false positives such as transient events like cosmic ray hits on WISE’s optics.
However, due to their close proximity to Earth and, therefore, their apparent high speed, many of the fastest asteroids were observed on less than five occasions.
The researchers decided to delve into the archived data to recover the small NEOs that are known to exist (as they were discovered by other telescopes), but were observed less than five times and therefore ignored as a true detection by the NEOWISE software.
Small objects zooming through the WISE field of view at relatively close distances can be tricky to track, a situation Mainzer likened to a speeding train.
“When you see a train from far away, it doesn’t seem to be moving very fast, but when you stand right next to it and it zips by you… now it looks like it’s moving really quickly,” Mainzer told Discovery News.
Many of these objects zoomed past the Earth at a distance of only a few Earth-moon distances, but their infrared signatures could still be used to evaluate the physical characteristics of these rocks.
One of the key findings of their work, which has been accepted for publication in the Astrophysical Journal (available also on the arXive pre-print service), is that visible light surveys likely have a bias against detecting small, dark asteroids.
“When we look at the visible light-selected sample - tiny NEOs discovered by ground-based surveys - we see a distinct trend; the smaller you go, the brighter the objects appear to be,” said Mainzer. “We know that visible light surveys are going to have a hard job of discovering objects that are both very tiny and very dark because they are faint to a visible light telescope.”
When analysing the selected NEOs (discovered in visible light) through WISE’s infrared data, they found that it’s likely that no such bias exists in infrared wavelengths.
Visible light surveys basically work by detecting the sunlight reflecting off asteroids’ surfaces. From visible light data, some idea as to the composition can be deduced.
However, infrared observations can reveal the physical size of the NEOs and the amount of heat that the asteroid is losing to space. The researchers noted that there is a strong relationship between heat flux (i.e. the thermal energy being emitted by the asteroids) and their physical sizes.
Also, there is little correlation between heat and reflectivity. In other words, if two asteroids are the same size, a bright asteroid will emit about the same amount of heat as a dark one. Therefore, an infrared telescope is roughly equally sensitive to dark and bright asteroids, whereas the dark asteroid looks fainter in visible light.
This observation alone gives pause for thought. If visible light surveys are biased toward seeing only the brightest (high albedo) space rocks, are a whole population of dark (low albedo) NEOs being under-detected?
In the coming months, astronomers will continue to study 2013 TV135 in order to improve calculations of the space rock’s orbit. Once more is understood about the asteroid, NASA scientists expect the risk of impact with Earth will be dramatically reduced, or even eliminated.
Initial observations of 2013 TV135 indicate that it follows an orbit that takes it as close to the sun as Earth, before swinging out three-quarters of the distance to Jupiter’s orbit.
Astronomers who have been monitoring 2013 TV135 say it takes almost four years for the space rock to complete one full orbit.
NASA’s Near-Earth Object Programme Office is tasked with finding, tracking and characterising asteroids and comets that may pose a threat to the planet. Yeoman and his colleagues use telescopes on the ground and in space to plot the orbital positions of these objects over time. Since October 14, a whopping total of 10,332 near-Earth objects have been newly discovered.
Many details of the asteroid’s orbital path are still unknown, but astronomers estimate it could be back in Earth’s neighborhood in less than 20 years. Still, NASA’s Near-Earth Object Programme Office, which monitors potential threats to the planet, says the probability that 2013 TV135 will impact Earth is only one in 63,000.
Also, the global space race is gathering momentum as India launches Mars probe. The forthcoming launch of a spacecraft to Mars by India is likely to stoke the fires of a burgeoning Asian space race.
The Indian Space Research Organisation (ISRO) is making its final preparations to send an orbiter to the Red Planet.
The principal aim is to test out India’s space technology to see if this emerging space-faring nation is capable of interplanetary missions. The spacecraft will also collect scientific information about the planet’s atmosphere and surface.
The Mangalyaan probe was to have been launched as early as October 28, but rough weather in the Pacific forced officials to delay the launch by a week. The unmanned mission has a launch window lasting until November 19.
If the mission succeeds, ISRO, will become only the fourth space agency, after those in the US, Europe and Russia to have successfully sent a spacecraft to Mars.
Meanwhile, astronomers have previously not been able to spot asteroids in the ‘blind zone’ due to radiation from the sun blocking information.
But now The European Space Agency (ESA) intends to launch the Gaia Space Telescope with its key task being to monitor the area between the Earth and the sun and warn of any impending collisions.
One recent asteroid, which could have been spotted as it travelled through the ‘blind zone’ months before it collided with the Earth, was that of the Russian asteroid of February this year, which caused a spectacular fireball before smashing into Chelyabinsk, 900 miles east of Russia.
Gerry Gilmore, professor of experimental philosophy at Cambridge University’s Institute of Astronomy told the Sunday Times: “Gaia will measure all the asteroids including those between us and the sun which are the really nasty ones because we can’t see them.”
During its five-year-mission the £800 million Gaia will also map the stars with unprecedented precision – giving astronomers the first accurate 3D map of our galaxy and measure distance between the stars.
A spokesman for the ESA said, “during its anticipated lifetime of five years, Gaia will observe each of its 1billion sources about 70 times, resulting in a record of the brightness and position of each source over time.
“Together with the unprecedented accuracy of the astrometric measurements, this will lead to the discovery of planets around other stars, asteroids in our Solar System, icy bodies in the outer Solar System, brown dwarfs, and far-distant supernovae and quasars.
“The list of Gaia’s potential discoveries makes the mission unique in scope and scientific return.”
NASA detects, tracks and characterises asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Programme, commonly called Spaceguard, discovers these objects, characterises a subset of them and identifies their orbits to determine if any could be potentially hazardous to our planet.
Also, the meteor that exploded over the Urals region of Russia in February was a violent reminder that our planet exists in a cosmic shooting gallery. Now, astronomers are focusing on these mysterious small and possibly dangerous objects in the hope of understanding what they are made of and what kind of threat they pose in the future.
Though rare, impact events by objects like the estimated 17-20 meter wide chunk of space rock can cause serious damage to populated regions. The city of Chelyabinsk suffered around 1,200 injuries and millions of dollars’ worth of property damage when the shock wave from the disintegrating meteor hit the ground - what if this happened to another city like New York, London or Moscow?
The fireball that lit up Russian skies on February 15 became the “poster child” for asteroid impact mitigation strategies and drew attention to the underfunded asteroid surveys that are currently our only defense against marauding near-Earth asteroids, or Near Earth Objects (NEOs). It also invigorated new research into the mysterious population of tiny asteroids that may not wipe out countries, but still give populated regions a very bad day.
In new research headed by Amy Mainzer, of NASA’s Jet Propulsion Laboratory in Pasadena, California, a population of NEOs smaller than 100 meters wide that invade our planet’s orbital space were studied using data from NASA’s Wide-field Infrared Survey Explorer (WISE). Taking their cue from small asteroid discoveries made by ground-based visible light surveys, 106 previously unreported infrared observations of small NEOs were analysed.
The new study published in Astrophysical Journal is titled “The Population of Tiny Near-Earth Objects Observed by NEOWISE.”
Inspired by the Chelyabinsk event, Mainzer and her team set out to survey this poorly-understood population of small NEOs. “What can we learn from these objects, particularly the small ones? What is the smallest object that we could see with WISE?” Mainzer asked.
WISE was used to carry out a wide-field survey of asteroids before the mission was put into hibernation in February 2011- a survey known as NEOWISE, of which Mainzer is principal investigator. The software used to analyse the NEOWISE data was set up to confirm the detection of asteroids that were observed five or more times, in order to avoid registering false positives such as transient events like cosmic ray hits on WISE’s optics.
However, due to their close proximity to Earth and, therefore, their apparent high speed, many of the fastest asteroids were observed on less than five occasions.
The researchers decided to delve into the archived data to recover the small NEOs that are known to exist (as they were discovered by other telescopes), but were observed less than five times and therefore ignored as a true detection by the NEOWISE software.
Small objects zooming through the WISE field of view at relatively close distances can be tricky to track, a situation Mainzer likened to a speeding train.
“When you see a train from far away, it doesn’t seem to be moving very fast, but when you stand right next to it and it zips by you… now it looks like it’s moving really quickly,” Mainzer told Discovery News.
Many of these objects zoomed past the Earth at a distance of only a few Earth-moon distances, but their infrared signatures could still be used to evaluate the physical characteristics of these rocks.
One of the key findings of their work, which has been accepted for publication in the Astrophysical Journal (available also on the arXive pre-print service), is that visible light surveys likely have a bias against detecting small, dark asteroids.
“When we look at the visible light-selected sample - tiny NEOs discovered by ground-based surveys - we see a distinct trend; the smaller you go, the brighter the objects appear to be,” said Mainzer. “We know that visible light surveys are going to have a hard job of discovering objects that are both very tiny and very dark because they are faint to a visible light telescope.”
When analysing the selected NEOs (discovered in visible light) through WISE’s infrared data, they found that it’s likely that no such bias exists in infrared wavelengths.
Visible light surveys basically work by detecting the sunlight reflecting off asteroids’ surfaces. From visible light data, some idea as to the composition can be deduced.
However, infrared observations can reveal the physical size of the NEOs and the amount of heat that the asteroid is losing to space. The researchers noted that there is a strong relationship between heat flux (i.e. the thermal energy being emitted by the asteroids) and their physical sizes.
Also, there is little correlation between heat and reflectivity. In other words, if two asteroids are the same size, a bright asteroid will emit about the same amount of heat as a dark one. Therefore, an infrared telescope is roughly equally sensitive to dark and bright asteroids, whereas the dark asteroid looks fainter in visible light.
This observation alone gives pause for thought. If visible light surveys are biased toward seeing only the brightest (high albedo) space rocks, are a whole population of dark (low albedo) NEOs being under-detected?
In the coming months, astronomers will continue to study 2013 TV135 in order to improve calculations of the space rock’s orbit. Once more is understood about the asteroid, NASA scientists expect the risk of impact with Earth will be dramatically reduced, or even eliminated.
Initial observations of 2013 TV135 indicate that it follows an orbit that takes it as close to the sun as Earth, before swinging out three-quarters of the distance to Jupiter’s orbit.
Astronomers who have been monitoring 2013 TV135 say it takes almost four years for the space rock to complete one full orbit.
NASA’s Near-Earth Object Programme Office is tasked with finding, tracking and characterising asteroids and comets that may pose a threat to the planet. Yeoman and his colleagues use telescopes on the ground and in space to plot the orbital positions of these objects over time. Since October 14, a whopping total of 10,332 near-Earth objects have been newly discovered.