Asteroid Bennu
A near-Earth asteroid that is coming towards our
planet after being dislodged by a gravitational pull can indeed strike us and
cause massive destruction, but according to experts, it has a only a one in
2,700 chances of hitting. Such an event will not take place for 150 years and
the people living in the year 2135 would know whether the asteroid named Bennu
posed an actual threat to hit Earth
OSIRIS-REx Mission
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It is headed by NASA and the University of Arizona, plans to launch an
unmanned spacecraft on September 8 in efforts to reach Bennu in August 2018.
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OSIRIS-REx will launch from Cape Canaveral, Florida, on an Atlas V 411
rocket
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In August 2018, OSIRIS-REx’s approach to Bennu will begin. It will use
an array of small rocket thrusters to match the velocity of Bennu.
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The spacecraft will begin a detailed survey of the asteroid two months
after slowing to encounter Bennu. After the selection of the final site, the
spacecraft will briefly touch the surface of Bennu to retrieve a sample
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The sampling arm will make contact with the surface for about five
seconds, during which it will release a burst of nitrogen gas. This will cause
rocks and surface material to be stirred up and captured in the sampler head
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In March 2021, the window for departure from the asteroid will open and
OSIRIS-REx will begin its return journey to Earth, arriving two and a half
years later in September 2023
What are asteroids?
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Asteroids are small, airless rocky worlds revolving around the sun that
are too small to be called planets. They are also known as planetoids or minor
planets.
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In total, the mass of all the asteroids is less than that of Earth’s
moon. But despite their size, asteroids can be dangerous.
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Many have hit Earth in the past, and more will crash into our planet in
the future.
What Are The Differences Between An Asteroid, Comet, Meteoroid, Meteor
and Meteorite?
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Asteroid
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Comet
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Meteoroid
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Meteor
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Meteorite
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A relatively small, inactive, rocky body orbiting the Sun
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A relatively small, at times active, object whose ices can vaporize
in sunlight forming an atmosphere (coma) of dust and gas and, sometimes, a
tail of dust and/or gas
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A small particle from a comet or asteroid orbiting the Sun
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The light phenomena which results when a meteoroid enters the Earth’s
atmosphere and vaporizes; a shooting star
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A meteoroid that survives its passage through the Earth’s atmosphere
and lands upon the Earth’s surface
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Most asteroids lie in a vast ring between the orbits of Mars and
Jupiter.
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Not everything in the main belt is an asteroid — for instance, comets
have recently been discovered there, and Ceres, once thought of only as an
asteroid, is now also considered a dwarf planet.
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Many asteroids lie outside the main belt. For instance, a number of
asteroids called Trojans lie along Jupiter’s orbital path.
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Three groups — Atens, Amors, and Apollos — known as near-Earth
asteroids orbit in the inner solar system and sometimes cross the path of Mars
and Earth.
Human Exploration of Asteroids
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The first spacecraft to take close-up images of asteroids was NASA’s
Galileoin 1991, which also discovered the first moon to orbit an asteroid in
1994.
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In 2001, after NASA’s NEAR spacecraft intensely studied the near-earth
asteroid Eros for more than a year from orbit, mission controllers decided to
try and land the spacecraft. Although it wasn’t designed for landing, NEAR
successfully touched down, setting the record as the first to successfully land
on an asteroid.
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In 2006, Japan’s Hayabusa became the first spacecraft to land on and
take off from an asteroid. It returned to Earth in June 2010, and the samples
it recovered are currently under study.
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NASA’s Dawn mission, launched in 2007, began exploring Vesta in 2011.
After a year, it left the asteroid for a trip to Ceres, with a planned arrival
time of 2015. Dawn was the first spacecraft to visit Vesta, and will also be
the first to explore Ceres.
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In 2012, a company called Planetary Resources, Inc. announced plans to
eventually send a mission to a space rock 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.
