Category The Universe, Exploring the Universe, Solar System, The Moon, Space, Space Travel

Why is Bennu being studied?

Over 200 million miles away from Earth, a spacecraft called OSIRIS REX studying the asteroid Bennu reached out its robotic arm to carry out a touch and go (TAG) manoeuvre at the site called Nightingale” to collect a sample from the asteroids surface on October 20. The one foot-wide sampling head made contact with Bennu’s surface for approximately 6 seconds, after which the spacecraft performed a back away bum. The sample will be returned to Earth in 2023.

What’s OSIRIS-REX mission all about?

NASA launched the sample-return mission OSIRIS REX (Origins, Spectral Interpretation, Resource Identification Security. Regolith Explorer) to the near Earth asteroid Bennu (officially 101955 Bennu) in 2016, OSIRIS-REX reached the proximity of Bennu in December 2018. It spent the next several months collecting and sending back data and images to help the NASA team on Earth learn more about the asteroid’s composition. In August 2019, NASA selected four candidate sample sites, namely Nightingale, Kingfisher, Osprey, and Sandpiper. In December 2019, Nightingale was confirmed to be the spot to carry out the mission’s primary goal of collecting sample from the asteroid’s surface.

What are the other objectives of the mission?

1) Mapping the asteroid

2) Documenting the sample site

 3) Measuring the orbit deviation caused by non-gravitational forces and

4) Comparing observations at the asteroid to ground-based observations.

What do we know about Bennu?

  • Bennu is a near-Earth asteroid, discovered in 1999.
  • It is as tall as the Empire State Building and located at a distance of about 200 million miles away from Earth.
  • It is a potentially hazardous object. It has one in 2,700 chances of impacting Earth between 2175 and 2199.
  • It is named after Bennu, an ancient Egyptian mythological bird,
  • Bennu is a “rubble pile” asteroid, which is a grouping of rocks held together by gravity.
  • Bennu completes an orbit around the Sun every 436.604 days and comes very dose to Earth every six years.
  • Bennu contains carbonaceous material which hints at the presence of water sometime in its mysterious past.
  • With the help of OSIRIS-REX, it was found that Bennu was ejecting material from its surface. Some of which fell back down, and some of which seemed to enter stable orbit.

How can the sample from Bennu help us understand the solar system better?

Scientists chose Bennu as the target of the OSIRIS REX mission because of its composition size, and proximity to Earth.

  • Bennu is classified as a B-tube asteroid which means it contains a lot of carbon and minerals. Bennu is a primitive asteroid that has not significantly changed since formation. Scientists have calculated that it might have formed in the first 10 million years of our solar system’s history over 4.5 billion years ago. Because of this, scientists hope to find organic molecules on Bennu like those that may have led to the origin of life on Earth
  • By studying Bennu, we can get a clearer picture about the formation of solar system.
  • Knowledge of Bennu’s physical properties will be critical for developing an asteroid impact avoidance mission in the future.

What next?

When going to press, NASA had not confirmed whether the arm had successfully collected sample from the surface following the touchdown. The goal was to collect at least 60 grams of sample from the surface.

If it has collected the spacecraft will prepare for its departure from Bennu in March 2021 – this is the next time Bennu will be properly aligned with Earth for the most fuel efficient return flight.

If it had failed to collect enough sample at Nightingale, then two more sampling attempts will be made. The next attempt will take place at the backup site called Osprey, which is another relatively boulder-free area inside a crater near Bennu’s equator, on Jan. 12. 2021. Whatever the case may be, the sample will be returned to Earth in 2023,

What are the other asteroid sample return missions?

OSIRIS-REX is the first asteroid sample return mission for NASA. But Japan has launched two such missions. It launched Hayabusa probe in 2003 to collect material from an asteroid called Itokawa. Things didn’t go entirely as planned, but Hayabusa did succeed in getting some tiny Itokawa grains to Earth in 2010

In December 2014, Japan launched Hayabusa 2, which collected sample in February 2019 and is scheduled to retum to Earth in December 2020.

 

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Which was the first animal launched into space?

The Soviet Union stunned the world on Nov. 3, 1957, with the launch of Sputnik 2. On board the small satellite was a little dog, Laika, the first animal to orbit Earth. However, Laika was not the first animal in space. The United States and the U.S.S.R. had been putting animals atop rockets since 1947.

Laika was a young, mostly-Siberian husky. She was rescued from the streets of Moscow. Soviet scientists assumed that a stray dog would have already learned to endure harsh conditions of hunger and cold temperatures. Laika and two other dogs were trained for space travel by being kept in small cages and learning to eat a nutritious gel that would be their food in space.

The dog’s name was originally Kudryavka, or Little Curly, but she became known internationally as Laika, a Russian word for several breeds of dog similar to a husky. American reporters dubbed her Muttnik as a pun on Sputnik.

Unfortunately, Laika’s trip into space was one-way only. A re-entry strategy could not be worked out in time for the launch. It is unknown exactly how long Laika lived in orbit — perhaps a few hours or a few days — until the power to her life-support system gave out. Sputnik 2 burned up in the upper atmosphere in April 1958.

 

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Who are three recipients of Nobel Prize for Physics in recognition of pioneering work?

The Nobel Prize in Physics was awarded to three astrophysicists Tuesday for work that was literally out of the world, and indeed the universe. They are Roger Penrose, an Englishman, Reinhard Genzel, a German, and Andrea Ghez, an American. They were recognized for their work on the gateways to eternity known as black holes, massive objects that swallow light and everything else forever that falls in their unsparing maws.

Black holes were one of the first and most extreme predictions of Einstein’s General Theory of Relativity, first announced in November 1915. The theory explains the force we call gravity, as objects try to follow a straight line through a universe whose geometry is warped by matter and energy. As a result, planets as well as light beams follow curving paths, like balls going around a roulette wheel.

Einstein was taken aback a few months later when Karl Schwarzschild, a German astronomer, pointed out that the equations contained an apocalyptic prediction: In effect, cramming too much matter and energy inside too small a space would cause space-time to collapse into a point of infinite density called a singularity. In that place — if you could call it a place — neither Einstein’s equations nor any other physical law made sense.

Einstein could not fault the math, but he figured that in real life, nature would find a way to avoid such a calamity.

 

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How many moons does Pluto have?

It is intriguing that such a small planet can have such a complex collection of satellites. The discovery provides additional clues for unraveling how the Pluto system formed and evolved.

Pluto’s entire moon system is believed to have formed by a collision between two the dwarf planet and another Kuiper Belt Object early in the history of the solar system. The smashup flung material that coalesced into the family of satellites observed around Pluto.

“The moons form a series of neatly nested orbits, a bit like Russian dolls,” said Mark Showalter of the SETI Institute.

The known moons of Pluto are:

  • Charon: Discovered in 1978, this small moon is almost half the size of Pluto. It is so big Pluto and Charon are sometimes referred to as a double planet system.
  • Nix and Hydra: These small moons were found in 2005 by a Hubble Space Telescope team studying the Pluto system.
  • Kerberos: Discovered in 2011, this tiny moon is located between the orbits of Nix and Hydra.
  • Styx: Discovered in 2012, this little moon was found by a team of scientists searching for potential hazards to the New Horizons spacecraft Pluto flyby in July 2015.
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Which dwarf planet is believed to have harboured a global subsurface ocean that likely froze long ago?

Remnants of an ancient water ocean are buried beneath the icy crust of dwarf planet Ceres — or, at least, lingering pockets of one. That’s the tantalizing find presented August 10 by scientists working on NASA’s Dawn mission. 

By far, Ceres is the largest object in the asteroid belt, which girdles the inner planets between Mars and Jupiter. But unlike its rockier neighbors, Ceres is a giant ice ball. It holds more water than any world in the inner solar except for Earth. That knowledge had long led some astronomers to suspect Ceres may have once had a subsurface ocean, which is part of the reason NASA sent the Dawn spacecraft there.

Ceres is the only dwarf planet in the inner solar system, and it locks up one-third of the entire mass in the asteroid belt. Astronomers think Ceres is a protoplanet, the fossilized remains of a world that never fully formed. But its growth was halted before it could become a full planet. Having such a history means Ceres likely holds an early record of our solar system’s primordial past — hence the name Dawn.

 

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Which are the four planets that are collectively known as plutoids?

According to International Astronomical Union (IAU), which began meeting in August of 2006, the term Plutoid now applies to Pluto, as well as any other small stellar body that exist beyond the range of Neptune.

Pluto was to these stellar objects what Ceres was to large objects in the asteroid belt – that is to say, comparable in size. Astronomers proposed several names for these objects, but matters did not come to a head until Eris was discovered. This dwarf planet was actually larger than Pluto, 2500 km in diameter, making it twenty-seven percent larger than Pluto.

In the end, the IAU could only resolve this matter by removing Pluto from the list of planets and devising a new category for dwarf planets that could no longer be considered true planets. Plutoid was the result, and now applies to the trans-Neptunian objects of Pluto, Haumea, Makemake, and Eris.

 

Picture Credit : Google