Tag: comets

NASA Spacecraft Finds Water In Search For Origins Of Life On Asteroid

A NASA spacecraft that just arrived last December 2018 on an asteroid has already made its first big discovery: ingredients for water.

Scientists hope that the OSIRIS-REx spacecraft will shed light on the mysteries of Bennu, an asteroid the size of a skyscraper that could hold clues to the origins of life on Earth.

The craft only arrived at the asteroid in recent days but the discovery of water is a major breakthrough that scientists hope can be matched by more discoveries in the future.

It was found when OSIRIS-REx flew close to the asteroid and picked up traces of hydrogen and oxygen molecules in its rocky surface. Those make up part of the recipe for water – itself a key ingredient in life itself.




The probe, on a mission to return samples from the asteroid to Earth for study, was launched in 2016. Bennu, roughly a third of a mile wide (500 meters), orbits the sun at roughly the same distance as Earth.

There is concern among scientists about the possibility of Bennu impacting Earth late in the 22nd century.

We have found the water-rich minerals from the early solar system, which is exactly the kind of sample we were going out there to find and ultimately bring back to Earth,” University of Arizona planetary scientist Dante Lauretta, the OSIRIS-REx mission’s principal investigator, said in a telephone interview.

Asteroids are among the leftover debris from the solar system’s formation some 4.5 billion years ago.

Scientists believe asteroids and comets crashing into early Earth may have delivered organic compounds and water that seeded the planet for life, and atomic-level analysis of samples from Bennu could provide key evidence to support that hypothesis.

OSIRIS-REx will pass later this month just 1.2 miles (1.9 km) from Bennu, entering the asteroid’s gravitational pull and analyzing its terrain.

From there, the spacecraft will begin to gradually tighten its orbit around the asteroid, spiraling to within just 6 feet (2 meters) of its surface so its robot arm can snatch a sample of Bennu by July 2020.

The spacecraft will later fly back to Earth, jettisoning a capsule bearing the asteroid specimen for a parachute descent in the Utah desert in September 2023.

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Pass it on: New Scientist

Asteroid or Comet: What’s the Difference?

Anything that comes close to the earth from outer space is known as a near-earth object (NEO).

These include asteroids and comets that may have been pushed out of their normal direction and then begin to head to earth.

While both comets and asteroids are included in this group, there are things that make them quite alike as well as different.

They are believed to be left over material from the beginning of our solar system, over 4 billion years ago.

In the early years of earth’s creation, many hit the earth and if you look at the moon you can still see the craters that are left by the impacts.

Both asteroids and comets played a major role in building our solar system, as we believe that in hitting the planets, they actually became part of the planets.

The difference between them is mainly what they are made of.  Comets are made of rock, ice and organic compounds. They are sometimes called ‘dirty snowballs’.

Although they are thought to have originally been made in the farthest sections of the solar system, they travel specific paths due to both planetary and the sun’s gravitational pull.

As a comet nears the heat source of the sun, the ice melts and creates a gas. When traveling, the gas is reflected by the sun and we can sometimes see it from the earth.




The gaseous ‘tail’ can be as long as thousands of miles. Scientists believe that when the earth was first forming, the water that is contained in the comets hit the earth and contributed to developing our oceans.

It’s also believed that this affected the climate and possibly deposited carbon-based molecules that may have helped to start life on the planet.

In ancient times, people thought that seeing a comet could be considered a ‘sign’. Some considered it bad, while other cultures thought it was good.

Asteroids are either made up of rock or rock and some metals, like nickel and iron.

Some asteroids look like one big piece while others are actually clusters of smaller pieces that are being held together with the gravity from the whole asteroid.

 

There are a small amount of asteroids that are actually burned out comets who lost all of their ice long ago and drift in space.

Almost all of the asteroids originate in the asteroid belt that is between Jupiter and Mars.  Jupiter’s massive gravity acts like a kind of guardian, keeping most of the asteroids away from earth.

Asteroids bang and knock into each other in the asteroid belt, and occasionally the force is strong enough to send one spinning into the solar system.

This puts all of the planets at risk from being hit.  Some of the smaller asteroids have come close to the earth and break up in the atmosphere. We call these ‘shooting stars’.

There are, however, a lot of larger asteroids in the solar system that could hit earth and do a lot of damage. Thankfully, we have Jupiter to help keep them away.

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Pass it on: Popular Science

Meteor, Comet Or Asteroid? How To Tell Them Apart.

Here’s how to tell a meteor from an asteroid from a comet.

Meteoroid: A small rocky or metal object, usually between the size of a grain of sand or a boulder, that orbits the sun. It originates from a comet or asteroid.

Meteor: A meteoroid that enters the earth’s atmosphere and vaporizes. Also called a “shooting star.”




Meteorite: A meteor that hits earth without burning up in the atmosphere.

Meteor shower: A collection of meteors visible when earth passes through a trail of debris left by a comet.

Asteroid: An object larger than a meteoroid that orbits the sun and is made of rock or metal. Historically, objects larger than 10 meters across have been called asteroids; smaller than that they’ve been called meteoroids.

Comet: A body of ice, rock and dust that can be several miles in diameter and orbits the sun. Debris from comets is the source of many meteoroids.

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Pass it on: Popular Science

Pluto May Have Formed From 1 Billion Comets

At its heart, Pluto may be a gigantic comet.

Researchers have come up with a new theory about the dwarf planet’s origins after taking a close look at Sputnik Planitia, the vast nitrogen-ice glacier that constitutes the left lobe of Pluto’s famous “heart” feature.

The European Space Agency’s Rosetta mission orbited Comet 67P/Churyumov-Gerasimenko from 2014 through 2016.

The orbiting mothership also dropped a lander named Philae onto the icy body, pulling off the first-ever soft touchdown on a comet’s surface.

Glein and his SwRI colleague Hunter Waite devised the new Pluto-formation scenario after analyzing data from Rosetta and NASA’s New Horizons mission, which flew by Pluto in July 2015.

The scientists also made some inferences about the dwarf planet’s evolution in their new study, which was published online Wednesday (May 23) in the journal Icarus.




Our research suggests that Pluto’s initial chemical makeup, inherited from cometary building blocks, was chemically modified by liquid water, perhaps even in a subsurface ocean,” Glein said.

Glein and Waite aren’t claiming to have nailed down Pluto’s origin definitively; a “solar model,” in which the dwarf planet coalesced from cold ices with a chemical composition closer to that of the sun, also remains in play, the duo said.

This research builds upon the fantastic successes of the New Horizons and Rosetta missions to expand our understanding of the origin and evolution of Pluto,” Glein said.

Using chemistry as a detective’s tool, we are able to trace certain features we see on Pluto today to formation processes from long ago,” he added.

This leads to a new appreciation of the richness of Pluto’s ‘life story,’ which we are only starting to grasp.”

Rosetta’s mission ended in September 2016, when the probe’s handlers steered it to an intentional crash-landing on 67P’s surface. New Horizons’ work, however, is far from done.

The NASA spacecraft is speeding toward a flyby of a small Kuiper Belt object known officially as 2014 MU69 (and unofficially as Ultima Thule).

This close encounter, which will occur on Jan. 1, 2019, about 1 billion miles beyond Pluto’s orbit, is the centerpiece of New Horizons’ extended mission.

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Pass it on: Popular Science