Sunday 21 April 2019

Asteroid 2019 GS19 passes the Earth.

Asteroid 2019 GS19 passed by the Earth at a distance of about 743 000 km (1.93 times the average distance between the Earth and the Moon, or 0.50% of the distance between the Earth and the Sun), slightly before 7.35 am GMT on Thursday 11 April 2019. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2019 GT19 has an estimated equivalent diameter of 14-45 m (i.e. it is estimated that a spherical object with the same volume would be 14-45 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) in the atmosphere between 20 and 10 km above the ground, with only fragmentary material reaching the Earth's surface.

The calculated orbit of 2019 GS19. Minor Planet Center.

2019 GS19 was discovered on 11 April 2019 (the day of its closest approach to the Earth) by the Palomar Transient Factory at Palomar ObservatoryThe designation 2019 GS19 implies that it was the 474th asteroid (asteroid S19 - in numbering asteroids the letters A-Y, excluding I, are assigned numbers from 1 to 24, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 25, A2 = 49, etc., which means that T19 = 18 + (24 X 19) = 474) discovered in the first half of April 2019 (period 2019 G).

2019 GS19 is calculated to have an 1015 day orbital period and an eccentric orbit tilted at an angle of 6.59° to the plane of the Solar System, which takes it from 0.82 AU from the Sun (i.e. 82% of the the average distance at which the Earth orbits the Sun) to 3.14 AU from the Sun (i.e. 314% of the average distance at which the Earth orbits the Sun, more than twice the distance at which the planet Mars orbits). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). This means that close encounters between the asteroid and the Earth occur occasionally, with the last calculated to have happened in April 1924 and the next predicted for May 2196. The asteroid also has occasional encounters with the planet Mars, with the last thought to have occurred in September 2007.

See also...

https://sciencythoughts.blogspot.com/2019/04/asteroid-2019-gt19-passes-earth.htmlhttp://sciencythoughts.blogspot.com/2019/04/fireball-meteor-over-new-jersey.html
http://sciencythoughts.blogspot.com/2019/04/the-lyrid-meteor-shower.htmlhttp://sciencythoughts.blogspot.com/2019/04/asteroid-2019-fl1-passes-earth.html
http://sciencythoughts.blogspot.com/2019/04/asteroid-7-iris-reaches-oposition.htmlhttp://sciencythoughts.blogspot.com/2019/03/asteroid-2019-fc1-passes-earth.html
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