3.5bn Years Ago, a River Used to Run Across Mars?

General Knowledge » Current Affairs »

3.5bn Years Ago, a River Used to Run Across Mars?

New astonishing pictures by the European Space Agency have revealed a 1,500km long and 7km wide river that once ran across Mars. The agency’s Mars Express imaged the striking upper part of the remnants of Reull Vallis river on Mars with its high – resolution stereo camera, ESA said.

Reull Vallis, is believed to have formed when running water flowed in the distant martian past, cutting a channel through the Promethei Terra Highlands before running on towards the floor of the vast Hellas basin. This structure, which stretches for almost 1,500 km, is flanked by numerous tributaries , one of which can be clearly seen cutting in to the main valley towards the upper ( north ) side.

The images show a region of Reull Vallis where the channel is 7 km wide and 300 m deep. The sides of Reull Vallis are sharp and steep. These structures are believed to be caused by the passage of loose debris and ice during the “Amazonian” period due to glacial flow along the channel. They were formed after it was originally carved by liquid water during the Hesperian period, which may have ended 3.5bn to 1.8bn years ago.

Nasa beams Mona Lisa to Moon with laser

In a major advance in laser communication, Nasa scientists have beamed a picture of Leonardo da Vinci’s masterpiece, Mona Lisa, to a powerful spacecraft orbiting the Moon. The first laser signal carrying the iconic image, fired from an installation in Maryland, beamed the Mona Lisa to the Moon to be received 384,400 km away by Nasa’s Lunar Reconnaissance Orbiter ( LRO ), which has been orbiting the Moon since 2009.

The Mona Lisa transmission is a major advance in laser communication for interplanetary spacecraft, Nasa scientists said. By transmitting the image piggyback on laser pulses, the team achieved simultaneous laser communication and tracking. The success of the laser transmission was verified by returning the image to Earth using the spacecraft’s radio telemetry system.

“This is the first time anyone has achieved one – way laser communication at planetary distances,” said Lunar Orbiter Laser Altimeter, LOLA’s principal investigator , David Smith of the Massachusetts Institute of Technology.

General Studies Question Bank CD

JEE Main

Application Form Submission 16 Dec 2020 to 16 Jan 2021.