Large Asteroid headed in Earth's Direction!

All those Star Trek acts of deflecting an asteroids and large bodies in space may come in handy when this new guy on the block comes after our planet. The space scientists may need their skills to get him off our back! For now, unlike earlier predictions, it is likely to miss Mars and fly right past it, making Earth its next target.

Designated 2007 WD5, the 160-foot wide asteroid was originally identified as a possible risk to Earth, though later analysis showed that it actually might be on a collision course with Mars.

According to a report in Discovery News, Donald Yeomans, a planetary scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, has said that the odds are that the asteroid is going to fly right past Mars.

In the long run, that may not be good news for Earth, which could find itself in the asteroid’s path at some point in the future. “Something of this size could take out a fairly large metropolitan area,” said Yeomans.

In 1908, a meteroid had blasted over Siberia in what is known as Tunguska event. The explosion was strong enough to destroy a large metropolitan area had it happened over a city. Many other such incidents have happened in the recent past, but were smaller in strength, so did not create any issues.

The Tunguska event was a scary one though as these accounts from Wikipedia tell us:

History on Tunguska Event

The Tunguska Event, sometimes called the Tunguska explosion, was a massive explosion that occurred near the Podkamennaya (Under Rock) Tunguska River in what is now Krasnoyarsk Krai of Russia, at 7:40 a.m. on June 30, 1908 Julian (July 13 Gregorian).

At around 7:15 a.m., Tungus natives and Russian settlers in the hills northwest of Lake Baikal observed a column of bluish light, nearly as bright as the Sun, moving across the sky. About 10 minutes later, there was a flash and a loud knocking sound similar to artillery fire that went in short bursts spaced increasingly wider apart. Eyewitnesses closer to the explosion reported the sound source moving during each barrage, east to north. The sounds were accompanied by a shock wave that knocked people off their feet and broke windows hundreds of miles away. The majority of eyewitnesses reported only the sounds and the tremors, and not the sighting of the explosion. Eyewitness accounts differ as to the sequence of events and their overall duration.

The explosion registered on seismic stations across Eurasia. Although the Richter Scale was not developed until 1935, it has been estimated that in some places the shock wave would have been equivalent to an earthquake of 5.0 on the Richter scale. It also produced fluctuations in atmospheric pressure strong enough to be detected by then recently invented barographs in Great Britain. Over the next few weeks, night skies were aglow such that one could read in their light, sometimes called bright nights. In the United States, the Smithsonian Astrophysical Observatory and the Mount Wilson Observatory observed a decrease in atmospheric transparency that lasted for several months.

The Guinness Book of World Records (1966 edition) states that due to the rotation of Earth, if the collision had occurred 4 hours 47 minutes later, it would have completely destroyed the Imperial Russian Capital City of Saint Petersburg (Leningrad).

Accounts of the event

* Testimony of S. Semenov, as recorded by Leonid Kulik’s expedition in 1930

“At breakfast time I was sitting by the house at Vanavara trading post (65 kilometres/40 miles south of the explosion), facing North. […] I suddenly saw that directly to the North, over Onkoul’s Tunguska road, the sky split in two and fire appeared high and wide over the forest (as Semenov showed, about 50 degrees up – expedition note). The split in the sky grew larger, and the entire Northern side was covered with fire. At that moment I became so hot that I couldn’t bear it, as if my shirt was on fire; from the northern side, where the fire was, came strong heat. I wanted to tear off my shirt and throw it down, but then the sky shut closed, and a strong thump sounded, and I was thrown a few yards. I lost my senses for a moment, but then my wife ran out and led me to the house. After that such noise came, as if rocks were falling or cannons were firing, the earth shook, and when I was on the ground, I pressed my head down, fearing rocks would smash it. When the sky opened up, hot wind raced between the houses, like from cannons, which left traces in the ground like pathways, and it damaged some crops. Later we saw that many windows were shattered, and in the barn a part of the iron lock snapped.”

* Testimony of Chuchan of Shanyagir tribe, as recorded by I.M.Suslov in 1926.

“We had a hut by the river with my brother Chekaren. We were sleeping. Suddenly we both woke up at the same time. Somebody shoved us. We heard whistling and felt strong wind. Chekaren said, ‘Can you hear all those birds flying overhead?’ We were both in the hut, couldn’t see what was going on outside. Suddenly, I got shoved again, this time so hard I fell into the fire. I got scared. Chekaren got scared too. We started crying out for father, mother, brother, but no one answered. There was noise beyond the hut, we could hear trees falling down. Chekaren and I got out of our sleeping bags and wanted to run out, but then the thunder struck. This was the first thunder. The Earth began to move and rock, wind hit our hut and knocked it over. My body was pushed down by sticks, but my head was in the clear. Then I saw a wonder: trees were falling, the branches were on fire, it became mighty bright, how can I say this, as if there was a second sun, my eyes were hurting, I even closed them. It was like what the Russians call lightning. And immediately there was a loud thunderclap. This was the second thunder. The morning was sunny, there were no clouds, our Sun was shining brightly as usual, and suddenly there came a second one!
“Chekaren and I had some difficulty getting out from under the remains of our hut. Then we saw that above, but in a different place, there was another flash, and loud thunder came. This was the third thunder strike. Wind came again, knocked us off our feet, struck against the fallen trees.
“We looked at the fallen trees, watched the tree tops get snapped off, watched the fires. Suddenly Chekaren yelled ‘Look up’ and pointed with his hand. I looked there and saw another flash, and it made another thunder. But the noise was less than before. This was the fourth strike, like normal thunder.
“Now I remember well there was also one more thunder strike, but it was small, and somewhere far away, where the Sun goes to sleep.”

* Sibir newspaper, July 2, 1908

“On the 17th of June, around 9 in the AM, we observed an unusual natural occurrence. In the N Karelinski village (200 verst N of Kirensk) the peasants saw to the North-West, rather high above the horizon, some strangely bright (impossible to look at) bluish-white heavenly body, which for 10 minutes moved downwards. The body appeared as a “pipe”, i.e. a cylinder. The sky was cloudless, only a small dark cloud was observed in the general direction of the bright body. It was hot and dry. As the body neared the ground (forest), the bright body seemed to smudge, and then turned into a giant billow of black smoke, and a loud knocking (not thunder) was heard, as if large stones were falling, or artillery was fired. All buildings shook. At the same time the cloud began emitting flames of uncertain shapes. All villagers were stricken with panic and took to the streets, women cried, thinking it was the end of the world. “The author of these lines was meantime in the forest about 6 verst N of Kirensk, and heard to the NE some kind of artillery barrage, that repeated in intervals of 15 minutes at least 10 times. In Kirensk in a few buildings in the walls facing north-east window glass shook.”