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

Is a missing moon responsible for Saturn’s rings and tilt?

Now known to host at least 83 moons, researchers propose that Saturn at one point must have had at least one more satellite, which they call Chrysalis

While all four gas giants – Jupiter, Saturn, Uranus, and Neptune – have rings, Saturn is the most popular ringed-planet. Swirling around Saturn’s equator, these rings indicate clearly that the planet is spinning at a tilt relative to the plane in which it orbits the sun.

For a long time, astronomers have suspected that this tilt is the result of Saturn’s interactions with neighbouring Neptune. A new modelling study by astronomers at Massachusetts Institute of Technology (MIT). however, suggests that while the two planets may have been in sync before, Saturn has since escaped Neptune’s pull.

Call it Chrysalis

In a study appearing in Science in September, the MIT team

posits that a missing moon might be responsible for this planetary realignment. Now known to host at least 83 moons, Saturn at one point must have had at least one more satellite that the researchers call Chrysalis.

The team estimates that after orbiting Saturn for several billion years, Chrysalis became unstable about 160 million years ago, coming too close to Saturn in the process. As the proposed satellite was long dormant before suddenly becoming active – just like a butterfly’s chrysalis – the researchers gave it the name Chrysalis.

The resulting encounter pulled the satellite apart and the loss of the moon was enough for Saturn to escape

Neptune’s grasp and leave it with its current tilt. Additionally, the researchers suggest that while most of Chrysalis’ shattered body may have impacted Saturn, a fraction of its fragments could have remained suspended in orbit. These could then have broken into small icy chunks to form the planet’s standout rings.

Explains two mysteries

The missing moon hypothesis, the researchers believe, could thus explain two mysteries pertaining to Saturn’s system. While one of these is Saturn’s present-day tilt, the other one is the age of its rings.

The rings are estimated to be about 100 million years old. very much younger than the planet itself. If the rings were indeed formed from fragments of Chrysalis, then the story fits perfectly.

Cassini’s inputs

The team of researchers arrived at this hypothesis by modelling the interior of Saturn. They identified a distribution of mass that matched the gravitational field that was observed by the Cassini spacecraft in its final phases. What they found indicated that Saturn is no longer in sync with Neptune, paving the way for researching various hypotheses, before arriving at their final result. The lead author of the study says that it is “a pretty good story, but like any other result, it will have to be examined by others”.

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WHAT IS JUPITER’S IO MOON?

Io or Jupiter I, is the innermost and third-largest of the four Galilean moons of the planet Jupiter. Slightly larger than Earth’s moon, Io is the fourth-largest moon in the Solar System, has the highest density of any moon, the strongest surface gravity of any moon, and the lowest amount of water (by atomic ratio) of any known astronomical object in the Solar System. It was discovered in 1610 by Galileo Galilei and was named after the mythological character Io, a priestess of Hera who became one of Zeus’s lovers.

With over 400 active volcanoes, Io is the most geologically active object in the Solar System.

This extreme geologic activity is the result of tidal heating from friction generated within Io’s interior as it is pulled between Jupiter and the other Galilean moons—Europa, Ganymede and Callisto. Several volcanoes produce plumes of sulfur and sulfur dioxide that climb as high as 500 km (300 mi) above the surface. Io’s surface is also dotted with more than 100 mountains that have been uplifted by extensive compression at the base of Io’s silicate crust. Some of these peaks are taller than Mount Everest, the highest point on Earth’s surface.  Unlike most moons in the outer Solar System, which are mostly composed of water ice, Io is primarily composed of silicate rock surrounding a molten iron or iron sulfide core. Most of Io’s surface is composed of extensive plains with a frosty coating of sulfur and sulfur dioxide.

Io’s volcanism is responsible for many of its unique features. Its volcanic plumes and lava flows produce large surface changes and paint the surface in various subtle shades of yellow, red, white, black, and green, largely due to allotropes and compounds of sulfur. Numerous extensive lava flows, several more than 500 km (300 mi) in length, also mark the surface. The materials produced by this volcanism make up Io’s thin, patchy atmosphere and Jupiter’s extensive magnetosphere. Io’s volcanic ejecta also produce a large plasma torus around Jupiter.

Io played a significant role in the development of astronomy in the 17th and 18th centuries; discovered in January 1610 by Galileo Galilei, along with the other Galilean satellites, this discovery furthered the adoption of the Copernican model of the Solar System, the development of Kepler’s laws of motion, and the first measurement of the speed of light. Viewed from Earth, Io remained just a point of light until the late 19th and early 20th centuries, when it became possible to resolve its large-scale surface features, such as the dark red polar and bright equatorial regions. In 1979, the two Voyager spacecraft revealed Io to be a geologically active world, with numerous volcanic features, large mountains, and a young surface with no obvious impact craters. The Galileo spacecraft performed several close flybys in the 1990s and early 2000s, obtaining data about Io’s interior structure and surface composition. These spacecraft also revealed the relationship between Io and Jupiter’s magnetosphere and the existence of a belt of high-energy radiation centered on Io’s orbit. Io receives about 3,600 rem (36 Sv) of ionizing radiation per day.

Further observations have been made by Cassini–Huygens in 2000, New Horizons in 2007, and Juno since 2017, as well as from Earth-based telescopes and the Hubble Space Telescope.

Credit : Wikipedia 

Picture Credit : Google 

Freakish wonders of the universe

The universe is full of deep mysteries and even the fraction of what we know is too fascinating for words. This month let’s take a look at some of the amazing yet scary inhabitants out there.

I’m coming to visit you

Black holes form when huge stars collapse and grow, taking up other objects around them. Think of them as giant invisible blenders that can tear apart planets even thousands of miles away. There aren’t black holes anywhere close to our solar system, but did you know that they can actually travel through space? And scarier still, rapidly-moving black holes cannot be detected! Scientists have assured us that space is a big place and black holes are quite rare – so sit back and relax!

A big show off!

Ever heard of gamma ray bursts? Well, they are considered as the brightest electromagnetic events to occur in the universe, so much so, that they can be seen billions of miles away! Are you also wondering how powerful they are? Apparently they emit as much energy in a few seconds that our sun can in 10 billion years! We’re glad that, like black holes, they are rare and far, far away from us.

Lone travellers

We imagine planets going around a star, endlessly orbiting it as long as they live. It turns out that not all planets exist this way. Astronomers have discovered a few Jupiter-sized planets drifting alone, without a place to call home or a star as a boss. They are thought to have been ejected out of their star system due to some massive explosion event. As long as they are not on a trajectory towards Earth, it’s dreamy fun to think about these lonely nomadic travellers.

What a blast!

Earth is like a magnet but its magnetic field is quite weak; an MRI machine can produce a magnetic field thousand times stronger. Since we can put our head in through the MRI machine, we can obviously put up with that magnetic field. But imagine a magnetic field that is a trillion times stronger than that of Earth. That’s the kind of power that a magnetar possesses! Come within 1000 kilometres of a magnetar and the very molecules that make you up can dissolve! Here’s a fun fact to freak you out in 2004, a magnetar located halfway across the Milky Way (500 quadrillion kilometres away) quaked and its effect was felt on the Earth’s upper atmosphere!

Mission Impossible

What if you stepped too close to a black hole but not quite? That’s exactly what hypervelocity stars did! They bolted away from the black hole at superfast speed. Hypervelocity stars were originally binary stars, of which one was captured and gobbled up by the black hole at the centre of our galaxy while the other lucky star was sent rocketing off at a very high speed, obviously very, very glad to escape.

Picture Credit : Google 

How an astronaut’s spacesuit is made?

One of the weirdest features in space travel is the spacesuit worn by astronauts, with its huge spherical helmet, the tunic, the bulky gloves and boots and all the various gadgets and fittings.

The space-suit is a highly perfected machine in itself. It consists of no fewer than fifteen layers of special materials to protect the body of the astronaut. The space suit must provide oxygen for the astronaut to breathe and protect the astronaut from the vacuum and heat or cold of space. It must also be flexible enough to allow the astronaut to move freely. For travel in space, the astronaut wears an MMU (manned maneuvering unit), which contains small gas-powered thrusters. 

The space-suit must also contain food and water supplies, fitting to dispose of bodily wastes and surface to deflect heat and radiation. The helmet visor requires protective tilters to prevent the astronaut from viewing the Sun directly and risking severe dazzling and retinal burns. The suit also has to be fireproofed to the maximum possible extent.

The space-suit took years and millions of dollars to develop.

 

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Which mission by NASA will land the first woman and next man on the Moon by 2024?

With the Artemis program, NASA will land the first woman and next man on the Moon by 2024, using innovative technologies to explore more of the lunar surface than ever before. We will collaborate with our commercial and international partners and establish sustainable exploration by the end of the decade. 

Following a successful hot fire test, the core stage will be shipped to the agency’s Kennedy Space Center in Florida for integration with the spacecraft. NASA will launch an SLS and an Orion together on two flight tests around the Moon to check performance, life support, and communication capabilities. The first mission – known as Artemis I – is on track for 2021 without astronauts, and Artemis II will fly with crew in 2023.

In the Phase 1 plan, NASA notes additional details about conducting a new test during the Artemis II mission – a proximity operations demonstration. Shortly after Orion separates from the interim cryogenic propulsion stage, astronauts will manually pilot Orion as they approach and back away from the stage. This demonstration will assess Orion’s handling qualities and related hardware and software to provide performance data and operational experience that cannot be readily gained on the ground in preparation for rendezvous, proximity operations, and docking, as well as undocking operations in lunar orbit beginning on Artemis III.

In 2024, Artemis III will be humanity’s return to the surface of the Moon – landing the first astronauts on the lunar South Pole. After launching on SLS, astronauts will travel about 240,000 miles to lunar orbit aboard Orion, at which point they will directly board one of the new commercial human landing systems, or dock to the Gateway to inspect it and gather supplies before boarding the landing system for their expedition to the surface.

Wearing modern spacesuits that allow for greater flexibility and movement than those of their Apollo predecessors, astronauts will collect samples and conduct a range of science experiments over the course of nearly seven days. Using the lander, they will return to lunar orbit before ultimately heading home to Earth aboard Orion.

Work is progressing rapidly on the Gateway. NASA will integrate the first two components to launch – the power and propulsion element and the habitation and logistics outpost – in 2023. This foundation for the Gateway will be able to operate autonomously, conducting remote science experiments when astronauts are not aboard. NASA has selected the first two science instrument suites to conduct space weather investigations in lunar orbit before crew visits.

 

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How many women have flown in space so far?

As of December 2019, of the 565 total space travelers, 65 have been women. There have been one each from France, Italy, South Korea, and the United Kingdom; two each from Canada, China, and Japan; four from the Soviet Union/Russia; and 50 from the United States. The time between the first male and first female astronauts varied widely by country. The first astronauts originally from Britain, South Korea, and Iran were women, while there was a two-year gap in Russia from the first man in space on Vostok 1 to the first woman in space on Vostok 6. The time between the first American man and first American woman in space was 22 years between Freedom 7 and STS-7, respectively. For China, this interval was almost eight and a half years between the Shenzhou 5 and Shenzhou 9 space missions, and for Italy, there was approximately twelve years between the STS-46 and Expedition 42 spaceflights.

A span of 19 years separated the first and second women in space. They were cosmonauts on the Vostok 6 and Soyuz T-7 missions. Though the Soviet Union sent the first two women into space, only four of the women in space have been Russian or Soviet citizens. However, British, French, Italian, dual-citizen Iranian-American and South Korean women have all flown as part of the Soviet and Russian space programs. Similarly, women from Canada, Japan, and America have all flown under the US space program. A span of one year separated the first and second American women in space, as well as the first and second Chinese women in space, taking place on consecutive missions, Shenzhou 9 and Shenzhou 10.

 

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