A near-earth asteroid named Bennu is likely coming towards the earth due to Gravitational pull and It can indeed hit the Earth causing massive destruction. According to experts, it has 1 in 2700 chances of hitting and such an event will not take place for 150 years.
People living in 2135 would know if Bennu posed actual threat to Earth.
OSIRIS-Rex Mission:
It is headed by NASA and University of Arizona, plans to send an unmanned spacecraft on Sept to reach Bennu in Aug 2018
OSIRIS-Rex will launch from Cape Canaveral, Florida on an Atlas V411 rocket.
According to their plans, OSIRIS-Rex’s approach to Bennu will begun by 2021.Its speed is matched to the speed of Bennu by array of small rocket thrusters. It touches Bennu for about 5 seconds, during which it will release burst of nitrogen gas. This will cause rocks and surface materials stirred up and it collects the sample.
By 2021, OSIRIS-Rex return will begun and it will reach earth by 2023.
What are asteroids?
Asteroids:
These are small objects revolving around sun and they are too small to consider as planets.
Comet:
A relatively small active object , whose ice can vaporize in sunlight forming atmosphere(coma ) of dust and gas / a tail of dust and gas
Meteoroid:
A small part of asteroid/comet orbiting sun
Meteor:
The light phenomena when a Meteoroid enters the earth’s atmosphere and vaporizes; a shooting star
Meteorite:
Meteor surviving the earth’s atmosphere and lands on earth’s surface.
Where are Asteroids located?
Most of the asteroids lie in a vast ring between Mars and Jupiter.
Not all the objects in the main belt are asteroids; For instance, comets have recently been discovered. Even Ceres, which is an asteroid is considered as Dwarf Planet.
Many asteroids lie outside the main belt. For instance, a group of asteroids called trojans, lie along the Jupitorial orbit path
Three groups- Atens, Armors, Apollos known as near-earth Asteroid groups, sometimes cross the path of Earth and Mars
Human Exploration:
The first spacecraft to take close up images of asteroid is NASA’s Galileoin NASA in 1991, which also discovered first moon to orbit an asteroid in 1994
In 2001, NEAR spacecraft sets the record of touching first asteroid by landing on Eros, a near-earth asteroid
In 2007, Japan’s Hayabusa become the first spacecraft to land and take off from an Asteroid.
NASA’s Dawn Mission launched in 2007, began exploring Vesta (second large object, after Ceres) in 2011. After a year, it left the asteroid and left to Ceres with planning arrival on 2015. Dawn is the first spacecraft to explore Vesta and will also be first to explore Ceres
In 2011, a private company called Planetary Resources Inc, has released a mission to extract water and mine the asteroid for precious metals. Since then, NASA has begun to work on plans for its own Asteroid-capture Mission.
