View larger. | Expected position in the sky of asteroid 2013 TX68 as of March 1, 2016, about 30 minutes after sunset. The space rock will be difficult to observe even with telescopes, especially if the asteroid passes at a great distance. At present, its distance at closest approach is not known. Illustration by Eddie Irizarry using Stellarium.
UPDATE February 29, 2016. Astronomers have continued to be able to refine the orbit of asteroid 2013 TX68, a space rock that will safely pass by Earth around March 8 at 00:06 UTC (March 7 at 7:06 pm ET). But its precise distance at its closest point is still not precisely known.
Marco Micheli of the European Space Agency’s NEO Coordination Centre (NEOCC/SpaceDys) in Frascati, Italy, realized that this object – which was observed only briefly in 2013 before going into a region of the sky lit by the sun’s glare – was visible on some images a few days before it was officially detected on October 6, 2013. The new images let scientists roughly refine its trajectory, but just a bit. It has been determined that the space rock’s closest possible approach to Earth in early March is farther than earlier thought.
The most recent estimate indicates the asteroid may pass at a nominal or most probable distance of 3,104,591 miles (4,996,355 km). However, the space rock may still pass as close as 19,000 miles (30,000 km) or as far as 10,722,990 miles (17,256,980 km). Astronomers at NASA’s Jet Propulsion Laboratory say the variation in possible nearest distances for this asteroid is due to the wide range of possible trajectories for this object, which was tracked for only a short time after its discovery in 2013.
Asteroid 2013 TX68 may pass by Earth around the evening of March 7 (according to clocks in the Eastern Time zone), but the time uncertainty is still 2 days. That means the space rock may be passing by our planet sometime between the evenings of March 5 and 9. The asteroid is travelling at a speed of 34,279 miles per hour (55,166 km/h).
If the new trajectory estimate is correct, there is no longer even a remote risk of impact in September, 2017, as earlier estimates had indicated.
Indeed, according to the latest orbit predictions, the next approach of asteroid 2013 TX68 will not be in 2017. It may pass by our planet again on September 18, 2056. However, the next closest approach dates predictions can change again, as soon as the asteroid is re-observed and its orbit is better understood and precisely defined.
Why is there so much uncertainty about this object?
It’s the scenario that astronomers have always cautioned us about … the fact that asteroid 2013 TX68 is approaching Earth from the sun’s direction. In late February, the space rock was still approaching Earth from this direction, although the asteroid was actually at a greater distance from us than our star. In other words, it has been in the daytime sky, and astronomers can’t observe it.
The uncertainty of the exact date of closest approach as well as the precise orbit, is due to the fact that asteroid 2013 TX68 was just observed during 10 days (including the newly found pre-discovery images). That is still a short time to define an orbit precisely. After it was observed and tracked for those few days in 2013, the asteroid passed into Earth’s daytime sky and could no longer be observed.
On February 11, 2016, NASA removed asteroid 2013 TX68 from a list of space rocks with possibilities of future impact with Earth over the next 100 years.
If the asteroid passes at its closest possible distance of just 19,254 miles (30,986 km), which seems unlikely, the flyby would still be even closer than orbiting communications satellites.
Preliminary estimates of the size of asteroid 2013 TX68 suggest the space rock has a diameter of 30 meters (98 ft), which is about twice the size of the Chelyabinsk meteor that entered over Russian skies in February, 2013.
If a space rock of this size were to enter our atmosphere, it would produce a shock wave at least twice as intense as that of the Chelyabinsk meteor, which broke windows in six Russian cities – caused more than 1,500 people to seek medical care, mostly due to cuts from flying glass – and did other damage to thousands of buildings.
How close will asteroid 2013 TX68 pass in early March? We will find out very soon, but scientists are not concerned. Paul Chodas, manager of NASA’s Center for Near-Earth Object Studies (CNEOS):
We already knew this asteroid, 2013 TX68, would safely fly past Earth in early March, but this additional data allow us to get a better handle on its orbital path.
The data indicate that this small asteroid will probably pass much farther away from Earth than previously thought.
Prospects for observing this asteroid, which were not very good to begin with, are now even worse because the asteroid is likely to be farther away, and therefore dimmer than previously believed.
Read more about asteroid 2013 TX68 at JPL’s site
Artist’s concept of an asteroid approaching Earth.
Orbit of asteroid 2013 TX68. The small arrow depicts the direction of the space rock, showing the asteroid is coming approximately from the sun’s direction, as seen from the perspective of Earth. Image via NASA/JPL-Caltech.
Bottom line: Astronomers know that asteroid 2013 TX68 will pass closest to Earth between March 5 and 9, 2016. It may pass farther than previously thought, but astronomers will better define its orbit very soon.
from EarthSky http://ift.tt/1QGZ25y
View larger. | Expected position in the sky of asteroid 2013 TX68 as of March 1, 2016, about 30 minutes after sunset. The space rock will be difficult to observe even with telescopes, especially if the asteroid passes at a great distance. At present, its distance at closest approach is not known. Illustration by Eddie Irizarry using Stellarium.
UPDATE February 29, 2016. Astronomers have continued to be able to refine the orbit of asteroid 2013 TX68, a space rock that will safely pass by Earth around March 8 at 00:06 UTC (March 7 at 7:06 pm ET). But its precise distance at its closest point is still not precisely known.
Marco Micheli of the European Space Agency’s NEO Coordination Centre (NEOCC/SpaceDys) in Frascati, Italy, realized that this object – which was observed only briefly in 2013 before going into a region of the sky lit by the sun’s glare – was visible on some images a few days before it was officially detected on October 6, 2013. The new images let scientists roughly refine its trajectory, but just a bit. It has been determined that the space rock’s closest possible approach to Earth in early March is farther than earlier thought.
The most recent estimate indicates the asteroid may pass at a nominal or most probable distance of 3,104,591 miles (4,996,355 km). However, the space rock may still pass as close as 19,000 miles (30,000 km) or as far as 10,722,990 miles (17,256,980 km). Astronomers at NASA’s Jet Propulsion Laboratory say the variation in possible nearest distances for this asteroid is due to the wide range of possible trajectories for this object, which was tracked for only a short time after its discovery in 2013.
Asteroid 2013 TX68 may pass by Earth around the evening of March 7 (according to clocks in the Eastern Time zone), but the time uncertainty is still 2 days. That means the space rock may be passing by our planet sometime between the evenings of March 5 and 9. The asteroid is travelling at a speed of 34,279 miles per hour (55,166 km/h).
If the new trajectory estimate is correct, there is no longer even a remote risk of impact in September, 2017, as earlier estimates had indicated.
Indeed, according to the latest orbit predictions, the next approach of asteroid 2013 TX68 will not be in 2017. It may pass by our planet again on September 18, 2056. However, the next closest approach dates predictions can change again, as soon as the asteroid is re-observed and its orbit is better understood and precisely defined.
Why is there so much uncertainty about this object?
It’s the scenario that astronomers have always cautioned us about … the fact that asteroid 2013 TX68 is approaching Earth from the sun’s direction. In late February, the space rock was still approaching Earth from this direction, although the asteroid was actually at a greater distance from us than our star. In other words, it has been in the daytime sky, and astronomers can’t observe it.
The uncertainty of the exact date of closest approach as well as the precise orbit, is due to the fact that asteroid 2013 TX68 was just observed during 10 days (including the newly found pre-discovery images). That is still a short time to define an orbit precisely. After it was observed and tracked for those few days in 2013, the asteroid passed into Earth’s daytime sky and could no longer be observed.
On February 11, 2016, NASA removed asteroid 2013 TX68 from a list of space rocks with possibilities of future impact with Earth over the next 100 years.
If the asteroid passes at its closest possible distance of just 19,254 miles (30,986 km), which seems unlikely, the flyby would still be even closer than orbiting communications satellites.
Preliminary estimates of the size of asteroid 2013 TX68 suggest the space rock has a diameter of 30 meters (98 ft), which is about twice the size of the Chelyabinsk meteor that entered over Russian skies in February, 2013.
If a space rock of this size were to enter our atmosphere, it would produce a shock wave at least twice as intense as that of the Chelyabinsk meteor, which broke windows in six Russian cities – caused more than 1,500 people to seek medical care, mostly due to cuts from flying glass – and did other damage to thousands of buildings.
How close will asteroid 2013 TX68 pass in early March? We will find out very soon, but scientists are not concerned. Paul Chodas, manager of NASA’s Center for Near-Earth Object Studies (CNEOS):
We already knew this asteroid, 2013 TX68, would safely fly past Earth in early March, but this additional data allow us to get a better handle on its orbital path.
The data indicate that this small asteroid will probably pass much farther away from Earth than previously thought.
Prospects for observing this asteroid, which were not very good to begin with, are now even worse because the asteroid is likely to be farther away, and therefore dimmer than previously believed.
Read more about asteroid 2013 TX68 at JPL’s site
Artist’s concept of an asteroid approaching Earth.
Orbit of asteroid 2013 TX68. The small arrow depicts the direction of the space rock, showing the asteroid is coming approximately from the sun’s direction, as seen from the perspective of Earth. Image via NASA/JPL-Caltech.
Bottom line: Astronomers know that asteroid 2013 TX68 will pass closest to Earth between March 5 and 9, 2016. It may pass farther than previously thought, but astronomers will better define its orbit very soon.
from EarthSky http://ift.tt/1QGZ25y
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