Big asteroid will safely pass Earth on Halloween
NASA says 2015 TB145 is the biggest known asteroid to sweep near Earth until 2027. It’ll pass at 1.3 times the moon’s distance and be visible through telescopes!
Artist’s concept of a large asteroid passing Earth, via Shutterstock.
A newly found asteroid of notable size will safely pass by Earth on October 31, 2015 and should be visible moving in front of the stars, with the help of a telescope, the night before. According to NASA, asteroid 2015 TB145 will be the biggest known asteroid to come near Earth until 2027. It was discovered just over a week ago, on October 10, from the Pan-STARRS I telescope in Hawaii. The Halloween asteroid’s closest approach will occur on 11:14 a.m. ET (15:14 UTC) on October 31, 2015.
Translate to your time zone here.
However, observers trying to glimpse the space rock using telescopes will have to look late on the night of October 30, and before dawn on October 31.
The huge asteroid will pass Earth at 310,000 miles (498,896 km) or 1.3 times the Earth-moon distance, which is a totally safe pass. It’ll come closer to the moon than to Earth, only 180,000 miles (280,000 km) from the moon.
The space rock’s brightness will be at an approximate magnitude of 10, which is fainter than the eye alone can see. But the asteroid should be easy to spot “slowly” moving across the field of stars if you know when and where to look. And, by the way, although the asteroid’s distance will make this moving object appear to move slowly, this speeding space rock is traveling at 78,000 miles (126,000 km) per hour!
On the night of October 30-31, the asteroid will be traveling across the well-known constellation of Orion.
View larger. | Facing east from central U.S. and similar latitudes at 11:50 pm CT on October 30, 2015. Illustration by Eddie Irizarry using Stellarium.
Preliminary estimates indicate asteroid 2015 TB145 is about 1,542 feet (470 meters) in diameter (estimates range between 689 to 2,133 feet, or 210 to 650 meters). Because of its size, advanced amateur astronomers may be able to see the moving asteroid in telescopes of 8″ in diameter or larger.
If the size is correct, the new found asteroid is 28 times bigger than the Chelyabinsk meteor that penetrated the atmosphere over Russia in February, 2013.
We are fortunate that asteroid 2015 TB145 is passing at a safe distance, because it was discovered so recently, only three weeks before its closest encounter with Earth. It’s a reminder of a comment made by NASA Administrator Charles Bolden in March, 2013, while addressing the U.S. House Science, Space, and Technology Committee at a meeting to discuss the threat of incoming asteroids like the Chelyabinsk meteor, which had happened just a month earlier. Bolden was trying to emphasize the need for adequate funding for detecting and characterizing near-Earth objects, and diverting them if necessary, when he told the committee:
From the information we have, we don’t know of an asteroid that will threaten the population of the United States. But if it’s coming in three weeks…pray.
Asteroid 2015 TB145, too – a large asteroid, discovered so recently – is a reminder of how important it is to support and improve the asteroid detection programs, such as NASA’s Near-Earth Object program. It’s also important to continue scientific studies about what might be done if a dangerous asteroid is detected on a possible collision course with Earth.
Various space agencies are already working towards earlier asteroid detections, but more funding is always required.
NASA is also planning to catch an asteroid, move it closer to our moon’s orbit, and then send astronauts to study how we can change the space rock’s orbit.
View larger. | Where to point your telescope: If you have a computerized (Go To) telescope, point it to HIP 23301, an 8 magnitude star in Orion before 2:20 a.m. CT on October 31 (Saturday morning) and wait for the asteroid. The space rock will appear as a slowly moving ‘star’ passing very close to this actual fixed star at that time. This view shows a half degree field of view (about the size of a full moon). Illustration by Eddie Irizarry using Stellarium.
Lance Benner, a NASA astronomer and asteroid expert said:
Asteroid 2015 TB145 will offer a great radar observations opportunity using the Goldstone Radar, the Green Bank antennas and may be the Arecibo Radio-Telescope in Puerto Rico.
NASA has said asteroid 2015 TB145 is the biggest known space rock to pass near Earth until 2027, when asteroid 1999 AN10 will safely pass by Earth.
In January, 2015 another asteroid, BL86 came some 1.2 million km (745,000 miles) from our planet. The 325 meter (1,100 ft) was also seen moving across the stars though telescopes.
Since asteroid 2015 TB145 appears to be bigger, and will pass even closer, its movement may be easier to spot than was the motion of asteroid BL86.
View larger. | Have a Go To computerized telescope? Point it to 15 Oioni (HIP 24010) a naked-eye star with a magnitude of 4.8 in Orion. At 4:20 a.m. CT on October 31 (Saturday morning), the space rock passes close to this star. The asteroid will appear as a slowly moving ‘star’ passing very close to this star. By this time the asteroid should appear to move faster because it will be closer to Earth than earlier on the night of October 30. This illustration shows a half degree field of view (about the size of a full moon). Illustration by Eddie Irizarry using Stellarium.
Bottom line: Asteroid 2015 TB145 – largest space rock to sweep near Earth until 2027 – will pass about 1.3 times the moon’s distance on October 31, 2015. Preliminary estimates indicate asteroid 2015 TB145 is about 1,542 feet (470 meters) in diameter, or about 28 times the size of the . Astronomers discovered it on October 10.
© 2014 Earthsky Communications Inc
http://earthsky.org/space/big-asteroid-will-safely-pass-earth-on-halloween-october-31-2015