"For forms of government let fools contest; that which is best administered is best. " -Alexander Pope. Critically examine the statement and state clearly wheter democracy is irrelevant to good governance in developing countries like India?.
NASA Probe Spots Evidence of Water on Asteroid Bennu
Post by Admin,Dec 13,2018.
Scientists have discovered evidence of water on asteroid Bennu, using data from NASA’s OSIRIS-REx spacecraft which recently reached the rocky cosmic body to unravel its mysteries. From August through early December this year, the spacecraft aimed three of its science instruments toward Bennu and began making the mission’s first observations of the asteroid.
During this period, the spacecraft travelled the last 2.2 million km of its outbound journey to arrive at a spot 19 km from Bennu on December 3.
Data obtained from the spacecraft’s two spectrometers reveal the presence of molecules that contain oxygen and hydrogen atoms bonded together, known as “hydroxyls.”
The team suspects that these hydroxyl groups exist globally across the asteroid in water-bearing clay minerals, meaning that at some point, the rocky material interacted with water.
While Bennu itself is too small to have ever hosted liquid water, the finding indicates that liquid water was present at some time on Bennu’s parent body, a much larger asteroid.
This finding may provide an important link between what we think happened in space with asteroids like Bennu and what we see in the meteorites that scientists study in the lab, said Ellen Howell, senior research scientist at University of Arizona’s Lunar and Planetary Laboratory (LPL) in the US.
The presence of hydrated minerals across the asteroid confirms that Bennu, a remnant from early in the formation of the solar system, is an excellent specimen for the OSIRIS-REx mission to study the composition of primitive volatiles and organics.
The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) is a NASA asteroid study and sample-return mission.
The mission's main goal is to obtain a sample of at least 60 grams (2.1 oz) from 101955 Bennu, a carbonaceous near-Earth asteroid, and return the sample to Earth for a detailed analysis.
The material returned is expected to enable scientists to learn more about the formation and evolution of the Solar System, its initial stages of planet formation, and the source of organic compounds that led to the formation of life on Earth.
OSIRIS-REx was launched on 8 September 2016, and reached the proximity of Bennu on 3 December 2018,where it began analyzing its surface for a target sample area over the next several months. It is expected to return with its sample to Earth on 24 September 2023.
101955 Bennu (provisional designation 1999 RQ36) is a carbonaceous asteroid in the Apollo group discovered by the LINEAR Project on 11 September 1999.
It is a potentially hazardous object that is listed on the Sentry Risk Table with the second-highest cumulative rating on the Palermo Technical Impact Hazard Scale.
It has a cumulative 1-in-2,700 chance of impacting Earth between 2175 and 2199.
101955 Bennu has a mean diameter of approximately 492 m (1,614 ft; 0.306 mi) and has been observed extensively with the Arecibo Observatory planetary radar and the Goldstone Deep Space Network.
Bennu is the target of the OSIRIS-REx mission which is intended to return samples to Earth in 2023 for further study.