Sentences with phrase «earth by comets»

This addition to the inventory of organic compounds produced in extraterrestrial environments furthers the discourse of whether their delivery to the early Earth by comets and meteorites might have aided the molecular evolution that preceded the origins of life.

Most researchers believe that the origin of life depended heavily on chemicals delivered to Earth by comets and meteorites.

While the origin of life remains mysterious, scientists are finding more and more evidence that material created in space and delivered to Earth by comet and meteor impacts could have given a boost to the start of life.

Not exact matches

Bits and pieces shed by this comet litter its orbit and bombard the Earth's upper atmosphere at 110,000 miles per hour (177,000 km / h).

This is no time for a child to be born, With the earth betrayed by war & hate And a comet slashing the sky to warn That time runs out & the sun burns late.

However, the Rosina mass spectrometer aboard Rosetta found that the ratio of deuterium to hydrogen in the comet is far greater than that found on Earth, adding to the growing body of evidence that the water on Earth was delivered not by comets, as previously thought, but by asteroids.

Fixing your moral compass and belief in God's message to a text written by people (strike that, by MALES) that thought the world was flat, the sun (and entire universe) revolved around the earth, that comets were angels, etc etc etc is a cop - out.

The comet hasn't returned and may be on a parabolic orbit, in which case it won't pass by Earth again.

The comet Siding Spring will pass by Mars at a distance of only 140,000 km, about a third of the distance from the Earth to the Moon, by way of comparison.

Earth is surrounded by a cloud of debris, both natural — such as micrometeorites and comet dust, which create meteor showers — and unnatural, including dead satellites and the cast - off detritus of space launches.

A dynamic simulation of that process, carried out by A'Hearn's colleague Kevin Walsh of Southwest Research Institute, sheds light on many long - standing puzzles about the solar system: not only where the Oort Cloud comets come from, but also why Mars is so small and airless com - pared with Earth.

First, planetary scientists suspect that cyanide was abundant on early Earth, deposited here by comets or created in the atmosphere by ultraviolet light or by lightning (once the atmosphere became oxygen rich, 2.5 billion years ago, the process would have stopped).

Earth and the other planets of our solar system suffer occasional impacts when comets are disturbed from their orbits around the sun by the gravity of nearby stars and gas clouds.

Unike Earth, Titan has no magnetic field of its own, but is surrounded by Saturn's rapidly rotating magnetic field, which drapes forming a comet - like tail around the moon.

Trigo states: «While it is true that many of these dangerous projectiles come from the main belt of asteroids after being gravitationally scattered towards the Earth by the so - called planetary resonances, in 2007 we proposed other physical mechanisms that enable these rocks to be detached from asteroids or comets as they undergo close approaches to our planet.»

The other finalist, the Comet Astrobiology Exploration Sample Return (CAESAR) mission, would launch a spacecraft before the end of 2025 to collect a 100 - gram sample from the surface of comet 67P, which was mapped by ESA's Rosetta spacecraft, and return it to Earth in 2038.

The glass itself, one large polished piece of which has a prominent place in a necklace that belonged to Egyptian pharaoh Tutankhamen, has been dated to 28.5 million years and has long been thought to be the result of a meteorite impact or an airburst caused by a comet breaking up in Earth's atmosphere.

The Perseid meteor shower occurs when Earth passes through debris left behind by the comet Swift - Tuttle, which last crossed the inner solar system in 1992.

By studying the gas, dust and structure of the nucleus and organic materials associated with the comet, via both remote and in - situ observations, the Rosetta mission should be a key to unlocking the history and evolution of our solar system, as well as answering questions regarding the origin of Earth's water and perhaps even life.

In January the Stardust spacecraft cruised by Earth and tossed down a 95 - pound canister packed with comet particles and interstellar dust, souvenirs scooped up during its seven - year journey past comet Wild 2.

Because the Explorer was «very tenuously held by Earth,» says Farquhar, it was relatively easy to break that connection in 1982 and send the craft off on an unplanned mission — to fly through the tail of the comet Giacobini - Zinner.

Instead, the Earth may have been bombarded by comets or asteroids for hundreds of thousands of years.

Balancing boulders on Earth are either deposited by glaciers or carved by wind and water erosion — none of which exist on a comet.

The theory, for example, that the dinosaur die - off was caused by Earth's collision with an asteroid or comet owes much to multidisciplinary efforts by astronomers, geologists, paleontologists, and chemists.

For example, another research team has already analyzed the gas and dust emitted by Wild 2, and astronomers look forward to January 2006 when a Stardust capsule containing thousands of comet dust particles will return to Earth for more thorough investigation.

Prematurely billed by the tabloids as the «killer comet» about to strike Earth, Hale - Bopp is fortunately not on a collision course with us.

Surveys funded by NASA's Near Earth Object (NEO) Observations Program (NEOs include both asteroids and comets) account for more than 95 percent of discoveries so far.

«It is believed that the Earth was initially dry, but our research strongly supports the view that the oceans we have today were created as a result of impacts by water - rich comets or asteroids.»

Another group has conducted experiments suggesting that the water at these depths was formed on Earth rather than being delivered by comets and asteroids.

Close encounters with Mars and Earth would give Rosetta enough speed to reach the comet Wirtanen by 2011.

In 2009, scientists reported that they had found the simplest amino acid, glycine, in comet dust brought back by NASA's Stardust spacecraft, but it's possible those samples were contaminated with dust from Earth.

In 2009, Elsila and her colleagues found the amino acid glycine in samples from comet Wild 2, gathered and brought back to Earth by NASA's Stardust mission.

«The detection of these compounds in comets helps to expand our knowledge of... the potential ingredients for life that could have been delivered to the early Earth or other planetary surfaces by comets,» says Jamie Elsila, an astrochemist at NASA.

For more than 30 years, scientists have argued about a controversial hypothesis relating to periodic mass extinctions and impact craters — caused by comet and asteroid showers — on Earth.

«This report is a reasonable step forward in trying to understand and come to grips with the hazards posed by asteroids and comet impactors,» said geophysicist Jay Melosh, a distinguished professor in the Department of Earth, Atmospheric and Planetary Sciences at Purdue University in Lafayette, Indiana.

In the 1980s, for example, researchers proposed that an unseen brown dwarf star could cause periodic extinctions on Earth by triggering fusillades of comets.

The cratering record on the moon provides a proxy for similar impacts by interplanetary debris such as comets and asteroids on Earth, the effects of which have largely been erased by billions of years of erosion and geologic activity.

He says he can find no evidence to support the idea, suggested by some geologists, that it might have come from comets or other bodies which pelted the Earth and Moon between 4.6 billion and 3.8 billion years ago.

In an October issue of Science, J. Matese and D. Whitmire at the University of Louisiana at Lafayette theorized that the comets are concentrated there by the long - sought - for Planet X, orbiting the sun within the Oort Cloud of comets at 25,000 times the Earth's distance from the sun.

One possibility called out by the authors would be icy comets bombarding Earth after formation and delivering their own distinct cocktail of compounds and gases to an existing atmosphere evolved from a solar source.

Planets can be born in the same way, so by tracing comets like 67P back to the pebbles that made them, we can find out more about what kinds of material made Earth.

Those results set the age boundary for the oldest terrains on Mercury to be contemporary with the so - called Late Heavy Bombardment (LHB), a period of intense asteroid and comet impacts recorded in lunar and asteroidal rocks and by the numerous craters on the Moon, Earth, and Mars, as well as Mercury.

By studying the gas, dust and structure of the nucleus and organic materials associated with the comet, the Rosetta mission should become key to unlocking the history and evolution of our solar system, as well as answering questions regarding the origin of Earth's water and perhaps even life.

If there is life on any Earth - type planet orbiting youthful Vega, it is likely to be primitive single - cell, anaerobic (non-oxygen producing) bacteria under constant bombardment by meteorites and comets as Earth was for the first billion years.

A 2007 paper led by W.B. Masse argued that asteroids and comets have struck Earth regularly in the longer past, so why has it been so quiet during our time?

If there is life on any Earth - type planet orbiting youthful Altair, it is likely to be primitive single - cell, anaerobic (non-oxygen producing) bacteria under constant bombardment by meteorites and comets as Earth was for the first billion years.

* Stochastic catastrophism * involves an assumption that Earth is hit randomly by lumps (asteroids, comets, meteoroids).

When it comes to life on Earth, we're not sure if it came from the outside (transported by comets) or on the inside.

The observations, published by the Astrophysical Journal Letters, also were significant because modest comets like Lemmon and ISON contain relatively low concentrations of crucial molecules, making them difficult to probe in depth with Earth - based telescopes.

Even if it is possible for an Earth - type planet to orbit youthful Sirius A and develop life, it is likely to be primitive single - cell, anaerobic bacteria under constant bombardment by meteorites and comets as Earth was for the first billion years.