Saturn is Losing its Rings: NASA

A view of Saturn's northern hemisphere.
(NASA/JPL-Caltech/Space Science Institute)

Saturn is losing its iconic rings at the maximum rate estimated from Voyager 1 and 2 observations made decades ago, confirms new NASA research that estimates that the rings have less than 100 million years to live.

Saturn's rings are mostly chunks of water ice ranging in size from microscopic dust grains to boulders several yards (metres) across. The rings are being pulled into Saturn by gravity as a dusty rain of ice particles under the influence of Saturn's magnetic field.

"We estimate that this 'ring rain' drains an amount of water products that could fill an Olympic-sized swimming pool from Saturn's rings in half an hour," said lead author of the study James O'Donoghue of NASA's Goddard Space Flight Center in Greenbelt, Maryland.

"From this alone, the entire ring system will be gone in 300 million years, but add to this the Cassini-spacecraft measured ring-material detected falling into Saturn's equator, and the rings have less than 100 million years to live. This is relatively short, compared to Saturn's age of over four billion years," O'Donoghue said.

Scientists have long wondered if Saturn was formed with the rings or if the planet acquired them later in life. The new research favours the latter scenario, indicating that they are unlikely to be older than 100 million years.

"We are lucky to be around to see Saturn's ring system, which appears to be in the middle of its lifetime. However, if rings are temporary, perhaps we just missed out on seeing giant ring systems of Jupiter, Uranus and Neptune, which have only thin ringlets today," O'Donoghue added.

Various theories have been proposed for the rings' origin. If the planet got them later in life, the rings could have formed when small, icy moons in orbit around Saturn collided, perhaps because their orbits were perturbed by a gravitational tug from a passing asteroid or comet.

The first hints that ring rain existed came from Voyager observations of seemingly unrelated phenomena: peculiar variations in Saturn's electrically charged upper atmosphere (ionosphere), density variations in Saturn's rings, and a trio of narrow dark bands encircling the planet at northern mid-latitudes.

These dark bands appeared in images of Saturn's hazy upper atmosphere (stratosphere) made by NASA's Voyager 2 mission in 1981.

The new study revealed glowing bands in Saturn's northern and southern hemispheres where the magnetic field lines that intersect the ring plane enter the planet.

Scientists analysed the light to determine the amount of rain from the ring and its effects on Saturn's ionosphere. They found that the amount of rain matches remarkably well with the astonishingly high values derived more than three decades earlier.

Why Isro's Gsat-7A launch is important for the Indian Air Force

HIGHLIGHTS

• The communication satellite will enable the Indian Air Force (IAF) to interlink different ground radar stations, airbases and AWACS aircraft
• Gsat-7A will not only interlink all airbases, but it will also boost drone operations
• It will boost the air force’s network-centric warfare capabilities and enhance its global operations

What is the need to launch a dedicated satellite for IAF?

Once GSLV-F11 (GSLV Mk II) rocket launches Gsat-7A satellite from the second launchpad at Sriharikota at 4.10 pm on Wednesday in the geo orbit, the communication satellite will enable the Indian Air Force (IAF) to interlink different ground radar stations, airbases and AWACS aircraft. It will boost the air force’s network-centric warfare capabilities and enhance its global operations.

Why is Gsat-7A important for IAF?

Gsat-7A will not only interlink all airbases, but it will also boost drone operations as it will help the force upgrade from existing ground control stations to satellite-control of military unmanned aerial vehicles (UAVs). The transition will boost the range, endurance and flexibility of UAVs. This comes at a time when India is in the process of acquiring American armed Predator-B or Sea Guardian drones, which are high-altitude and long endurance satellite-controlled UAVs that can fire at enemy targets from long distances.

What are the features of Gsat-7A?

Costing around Rs 500-800 crore, the communication satellite is configured on the standard 1-2K Bus with bi-propellant chemical propulsion system for orbit rasing and in-orbit maintenance. Its four solar panels are capable of generating around 3.3 kilowatts of electrical power.

How many dedicated communication satellites Isro has launched for the military?

Before the scheduled launch of Gsat-7A, Isro had launched Gsat-7, also called ‘Rukmini’, on September 29, 2013 exclusively for the Navy. ‘Rukmini’ has helped the Navy monitor the Indian Ocean Region (IOR) as the satellite has a nearly 2,000 nautical mile ‘footprint’ and provides real-time inputs to Indian warships, submarines and maritime aircraft. The IAF is also likely to get another satellite Gsat-7C, within a few years that will boost its network-centric operations.

What are the space assets of our Indian military?

India currently possesses around 13 military satellites. Most of these remote-sensing satellites like Cartosat-series and Risat satellites are placed in the near-earth orbit which help in better scanning of the earth. However, some of these military satellites have also been put in the geo orbit. The forces use these satellites for surveillance, navigation and communication purpose. The remote sensing satellites had also helped the military in the surgical strike against Pakistan to destroy terror launchpads.

How many military satellites are there in the world?

Currently, there are 320 military satellites orbiting the earth, with the US owning half of them, followed by Russia and China. Of late, China, considered to be India’s biggest rival, has taken huge strides in developing military assets in space, testing even ASAT (anti-satellite) weapons against “low-earth satellites” in January 2017.

Meet Farout, the Solar System’s Most Distant Minor Planet

Observations suggest the object is 300 miles in diameter, pinkish-red and 3.5 times as far away from the sun as Pluto

According to Sarah Lewin at Space.com, Farout—whose official name is 2018 VG18—was first spotted in November by researchers using the Subaru 8-meter telescope in Hawaii. Its existence was then confirmed using the Magellan telescope at Las Campanas Observatory in Chile. Those observations show that the object is about 300 miles across and spherical, making it a dwarf planet. Its pinkish color also suggests that it is covered in ice. The celestial body was found about 120 astronomical units (AU) away, or 120 times the distance of the Earth to the sun. For comparison, Pluto orbits at 34 AUs and Eris, the former farthest observed object in the solar system, is 96 AUs away.

NASA Predicts That A 4 Kilometer Wide Asteroid Will Zip Past Earth On 1 September

Asteroids are whizzing past Earth all the time, though they don’t come too close to hitting us. NASA has now predicted another fly by the incident to occur next month, but it’s slightly different.

For one thing, the space agency is saying the rock that’ll hurtle past us is the largest near-Earth object (NEO) we’ve seen since we began tracking them 20 years ago.

Measuring 4.4 km across, asteroid Florence, as it’s called, is more than large enough to cause massive destruction, were it to hit Earth. Even the 20 m wide Chelyabinsk meteorite that made contact in 2013 wrought havoc, and any object larger than 1 km impacting Earth could cause a global extinction. And NASA has tracked over 880 such NEOs in our vicinity.

But, though asteroid Florence is about making its closest pass of Earth at a distance of 7 million km, the space agency there’s no chance of a collision anytime in the next 500 years.

“While many known asteroids have passed by closer to Earth than Florence will on September 1, all of those were estimated to be smaller,” says Paul Chodas, manager of NASA's Center for Near-Earth Object Studies (CNEOS). “Florence is the largest asteroid to pass by our planet this close since the NASA program to detect and track near-Earth asteroids began.”

The rock will zip past our planet on September 1, and will be visible to small telescopes for a few nights from late August to early September.

Stephen Hawking Says The Human Race Has No Future If It Doesn't Go To Space

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Some believe that our breaths are numbered, but according to Stephen Hawking, so are our days on earth.

Just of late we heard about the huge plans that Elon Musk has for us, and now, Hawking is kind of validating the research that could change the face of life on earth.

According to Professor Hawking, science is most likely to produce an advancement which will wipe out our existence from the earth within 1,000 - 10,000 years.

Stephen Hawking says the human race has no future if it doesn't go to space https://t.co/6lMxFwrEkg

— TIME (@TIME) September 26, 2016

'I believe that life on Earth is at an ever-increasing risk of being wiped out by a disaster, such as a sudden nuclear war, a genetically engineered virus, or other dangers,' he said.

He also says that human race will have no future if it doesn’t go to space.

In his book "How to make a spaceship” he has given detailed answers to all such questions and emphasised on the idea of why it is necessary for mankind to start considering colonisation on other planets.

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Next space station crew to launch next week; NASA to air live coverage!

Ever since Expedition 48 crew members, NASA astronaut Jeff Williams, along with Oleg Skripochka and Alexey Ovchinin of the Russian Roscosmos, made their way back to Earth, space enthusiasts have been wondering about the next batch of astronauts who will be taking over the International Space Station (ISS) for Expedition 49.

Cassini gets ready for closest-ever observations of Saturn

Washington: NASA's Cassini spacecraft has entered the final year of its epic voyage during which it will make the the closest-ever observations of Saturn and its rings.

The conclusion of the historic scientific odyssey is planned for September 2017, but not before the spacecraft completes a daring two-part endgame, NASA said in a statement on Friday.