If you were, you were certainly breathing a sigh of relief,that it did not hit the Earth. If you were not, then, yes an asteroid passed by the Earth of January 13th,2010 at only a
distance of 78,000 miles (which is about one third of the distance between the Earth and the Moon!
Here is a fly-by animation of asteroid 2010 AL30, which I found had been posted to Youtube by Dave and which shows how close it came to the earth! Whew!
Here are some facts about Asteroid 2010 AL30:
Earlier reports had suggested the object might be man-made, but according to NASA's Jet Propulsion Laboratory's Small Body Database, 2010 AL30 has now been classified as an "Apollo" class near- Earth asteroid (NEA). According to the website: http://www.enchantedlearning.com/subjects/astronomy/asteroids/nea.shtml
"An NEA is an asteroid whose orbit brings them within 1.3 AU (121 million miles/195 million kilometers) of the Sun are called Near-Earth Asteroids (NEA) or Earth-Approaching asteroids. These asteroids probably came from the main asteroid belt, but were jolted from the belt by collisions or by interactions with other objects' gravitational fields (primarily Jupiter)."
"About 250 NEAs have been found so far, but many, many more exist. The largest known NEA is 1036 Ganymede, with a diameter of 25.5 miles (41 kilometers). According to astronomers there are at least 1,000 NEA's whose diameter is greater than 0.6 miles
(1 kilometer) and which could do catastrophic damage to the Earth. Even smaller NEA's could cause substantial destruction if they were to collide with the Earth."
There are three types of NEA's:
- Amors (named for asteroid Amor, #1221): Asteroids which orbit between the orbits of Earth and Mars. Eros (#433) is an Amor.
- Apollos (named for asteroid Apollo, #1862): Asteroids which cross Earth's orbit and have a period longer than 1 year. They have semimajor axes greater than 1 astronomical unit (AU), and perihelion distances less than 1.017 AU. Geographos is an Apollo.
- Atens (named for asteroid Aten, #2062): Atens are asteroids that are always closer to the Sun than the Earth is; they have a period shorter than 1 year (the semi-major axis is smaller than Earth's). Ra-Shalom is an Aten.
Experts in the field of Astronomy estimate that Some 20 percent of the near-Earth asteroids are Baptistina-family escapees.
What is a Baptistina-family escapee asteroid you ask?
According to Dr. Richard Cowan in an article published in the September 8,2007 Science News: (source:http://findarticles.com/p/articles/mi_m1200/is_10_172/ai_n27382296/)
The Answer is:
"A huge chunk of rock hit Earth 65 million years ago, setting off events that wiped out the dinosaurs. That chunk, astronomers now say, was a wayward fragment from a collision between two giant asteroids in the inner part of the asteroid belt, which lies between Mars and Jupiter. The new study adds to the evidence that both Earth and moon have been bombarded by about twice the usual number of asteroid fragments during the past 200 million years."
"The Earth is now at the tail end of this asteroid shower, say Bill Bottke of the Southwest Research Institute in Boulder, Colo., and his colleagues in the Sept. 6, 2007 Nature." (See the following website: http://www.nature.com/nature/journal/v449/n7158/).
"The researchers began their study by pondering the pattern of craters on 951 Gaspra, a member of the Flora family of asteroids. Searching for objects that could have caused the impacts, the team examined a much darker, harder-to-detect group of asteroids, the Baptistina family, that resides close to the belt's inner edge and near the Flora family."
"Bottke and his colleagues were intrigued to find that the Baptistina family stretches over a region containing two gravitational-escape hatches, places where a gentle nudge could kick an asteroid out of the belt and into the inner solar system toward Earth. Once ejected, members of the Baptistina family could wallop a lot more objects than just Gaspra."
"Tracing the paths of the Baptistina asteroids back in time, the researchers calculate that the objects originated as a single, 170-kilometer-wide body that was shattered by another big rock in the belt some 160 million years ago. About 20 percent of the Baptistina family escaped the belt, and about one-tenth of those asteroids would have continued on to Earth, doubling the number of objects striking the planet over the past 150 million years, Bottke and his collaborators say. Some 20 percent of the near-Earth asteroids are Baptistina-family escapees, they estimate."
"This is an amazing result and shows that recent events [in the asteroid belt] can strongly influence our impact history," says planetary scientist Derek Richardson of the University of Maryland at College Park."
"To link these findings to the death of the dinosaurs, Bottke's team examined the composition of the 180-km-wide Chicxulub crater in Mexico. Most scientists accept the crater as proof that a space object collided with Earth 65 million years ago, causing the mass extinction at that time."
"Sediments from the crater indicate that the impactor must have been a carbonaceous chondrite, an especially primitive meteorite. Such rocks have compositions matching that of the Baptistina asteroids but not that of several other candidates. Bottke's team calculates a 90 percent chance that the dinosaur killer came from the Baptistina family."
"Dead is dead, no matter where the bullet came from; notes asteroid researcher Alan W. Harris of the Space Science Institute in La Canada, Calif. What's most important, he says, is that the team, studying recent data on hundreds of thousands of asteroids, has dated the origin of this family and argued that it eventually sprayed an "asteroid shower" toward Earth."
"Another escapee from the Baptistina family probably gouged the 85-km-wide Tycho crater on the moon, the team suggests." (source:
Dr. Cowan (Ph.D.,Cambridge (1966) is a Senior Lecturer Emeritus at the University of California Davis.
What is really important about the finding of Asteroid 2010 AL30 is this:
"Planetary scientists suggest that the asteroid gives us a new standard: a 10-meter-wide asteroid can be detected two days before it potentially hits Earth. A pretty useful warning if you ask me."
(source: http://news.discovery.com/space/the-2010-al30-an-asteroid-or-man-made-object.html )
So in reality, the close passage of Asteroid 2010 AL20 has been a blessing for scientists and all of us on the planet, because now scientists have proof that their prediction methods can be utilized to activate technology which will be able to destroy or deflect asteroids which may have destroyed us all on our planet!
In closing this blog entry here are some other facts about Asteroid 2010 AL30:
1.AL30 has an orbital period of almost exactly one year.
2. As stated by Dr. Ian O'Neil who is Space Producer for Discovery News,
"It is worth noting that even if 2010 AL30 did hit Earth, it would most likely explode high in the atmosphere (with the energy of a small nuclear bomb), posing little danger to anyone on the ground. Impacts of this size happen every year."
Dr. O'Neil maintains a very interesting blog at the following web address:
Here is a link to video which shows AL30 as it passed by the Earth .The video was taken through a high-powered telescope which was on the Earth: