Sentences with phrase «of known asteroids»

Then they searched a database of known asteroids for ones that could have produced rocks that follow those orbits.

Not exact matches

As we face future known threats like war and climate change, and unknown threats like an asteroid impact or new disease, Downey said that that's the kind of knowledge we should want to have.

Getting economists to describe it is a bit like asking an astrophysicist to give you a detailed picture of what would happen if a giant asteroid hit the earth — no one really knows because, thank goodness, it has never happened before.

While I no longer believe the earth is just 6,000 years old, I still live in the tension of unanswered questions about the universe, and death, and brains, and Neanderthals, and whatever Neil deGrasse Tyson's got to say on public television about the earth getting burned up by the sun or our species going extinct after an asteroid hits.

We know of only one lineage of primates, a little form called purgatorius that lived before this potential asteroid hit.

We know of only one lineage of primates, a little animal called Purgatorius, that lived before this hypothetical asteroid hit.

No longer does playing a game mean that your child is spending mindless hours in front of a TV shooting aliens or asteroids.

Over 30 years ago, scientists proposed a large asteroid impact to explain the disparate elevations of Mars» northern and southern hemispheres; the theory became known as the «single impact hypothesis.»

The meteorite, dubbed Northwest Africa (NWA) 7034, contains a concentration of water by weight about ten times higher than in any of the other 100 or so known Martian meteorites — those rare rocks that get ejected from the Martian surface into space when an asteroid hits the planet, and eventually find their way to Earth.

Astronomers knew the initial solar system was full of tiny rocks, and somehow they grew into planets, asteroids and everything else.

Software on Tucker's computer compares his fresh images with maps of known stars and asteroids.

Since his facility boasts one of the most powerful privately owned telescopes in the country, he has also worked with NASA on projects like tracking the orbits of hundreds of faintly visible known asteroids to determine whether they are on a collision course with Earth.

This map shows the overlapping orbits (blue) of the 1,400 known Potentially Hazardous Asteroids — objects more than about 400 feet wide that can approach within 4.6 million miles of Earth.

Researchers have also searched for the existence of some asteroid, among all known, that may have been fragmented and resulted in the meteorite.

Currently, 1,573 asteroids of this type are known so researchers are investigating to what extent they can pose a danger.

When a known asteroid passed within 28,000 kilometers of Earth on February 15, astronomers hoped it would serve as a wake - up call about the danger of meteorite impacts.

«It's been known for 15 years that about 15 per cent of near - Earth asteroids are binary,» says Katarina Miljkovic at the Institute of Earth Physics in Paris, France.

«Now we know where not to point the camera,» says Cheng, referring to large shadowed regions of the asteroid's surface visible in the new images.

Almost nothing is known about the dinosaurs that lived in Africa at the end of the Cretaceous period 66 million years ago, just before they were wiped out by the impact of a giant asteroid.

One middle - aged star, known as HD 69830, appears to be surrounded by an asteroid belt that is 25 times as dense as the one in our solar system, possibly the remnants of a rocky planet that never formed.

He also has spotted a number of previously known asteroids, and also thought he discovered a near - Earth asteroid — the kind that can threaten Earth — but it wasn't seen again.

«We identified all known families and their members and discovered a gigantic void in the main belt, populated by only a handful of asteroids.

The team used a new search technique that also identified the oldest known asteroid family, which extends throughout the inner region of the main asteroid belt.

We now know that hordes of asteroids pass close to our planet, some closer than the Moon itself.

About 1 percent of these ice - infused boulders, known as C - type asteroids, were dropped into the outer regions of the asteroid belt.

When we look at rocks below that size, the gap between the number of asteroids we've seen and the number we think are out there widens (see graph below), according to a recent paper published in the journal Icarus that lays out the known unknowns.

Two years ago astronomers found Quaoar, the largest known member of a remote fringe of asteroids called the Kuiper belt.

Here's how we know: astronomers can estimate how many asteroids of a given size are out there, even if we haven't seen them all, by looking at the rate of re-detection, or how often we see the same asteroid a second time.

Morever, because Bennu has a slight - but - significant chance of striking our planet late in the 22nd century, it is also one of the most threatening asteroids known to humanity.

«Catalog of known near - Earth asteroids tops 15,000.»

The results are somewhat unexpected because comets, the icier cousins of asteroids, are known typically to sprout jets and plumes, while objects in the asteroid belt are not.

It appears similar to a group of asteroids known as carbonaceous chondrites.

Nonetheless, tens of thousands of asteroids are currently known, and estimates of the total number range in the millions.

«We know of thousands of binaries similar to SDSS 1557 but this is the first time we've seen asteroid debris and pollution.

With NASA's release today of the latest image from the approaching Dawn spacecraft, asteroid Vesta is no longer a fuzzy, nearly featureless ball; it's a surprisingly youthful world, geologically speaking, sporting still - mysterious features.

Previously rendered only in artists» conceptions, the first asteroid collision known in modern times revealed itself in a tail of debris streaming from what astronomers at first assumed was a comet.

There's a slim chance 1950 DA will hit Earth in 2880, and thanks to this finding, we'll know blasting the asteroid apart would be worse than useless: A strike might create multiple jumbles of rocks (held together with van der Waals» forces and gravity) heading our way.

Well, Vulcan doesn't exist — Albert Einstein's general theory of relativity explains Mercury's orbit — but asteroids known as vulcanoids could, circling so close to the sun that we can't see them in its glare.

Even before astronomers pointed their telescopes at a dim star over Chile last June, they knew it would darken for a few seconds as an asteroid passed in front of it.

Some asteroids are known to be rich in water, and some of these would inevitably have crashed into Earth during the chaotic early days of the solar system.

Once regarded as «vermin of the skies,» asteroids are now known to offer important clues to the birth of the solar system.

«From what we know of the asteroids we've been to, they have boulders on the surface,» he said, which means mission controllers would have many choices for which one to grab.

If that idea is correct, then it implies that the moon's water is mostly ancient — contrary to scientists who have argued that water was delivered more recently by asteroid impacts or even produced by a hail of protons known as the solar wind.

That feature — in which the crust thickness drops from 30 to about 10 miles (50 to 20 kilometers) over a large area that is the most visible feature on Mars — has been known to astronomers for more than 30 years and was long suspected to be due to an asteroid impact that flung most of the crust out the area.

There are only a dozen known asteroids and dwarf planets with enough mass to boil the oceans (2x10 ^ 18 kg), these include (Vesta 2x10 ^ 20 kg) and Pluto (10 ^ 22 kg), however none of these objects will intersect Earth's orbit and pose a threat to tardigrades.

An asteroid a few metres across passed 150 000 kilometres from the Earth on 20 May, the closest any asteroid has ever been known to come to our planet, says Dan Green of the Harvard Smithsonian Center of Astrophysics.

Two teams reported complementary observations of the 200 - kilometer - wide asteroid, known as 24 Themis, in the April 29 Nature.

This view of 1,000 - mile - wide Caloris basin — among the largest known asteroid impacts in the solar system — shows how lava (orange) filled the blast site before new craters excavated the original basin (purple).

Neptune, for example, does not prevent Pluto from crossing its orbit, and Jupiter's orbit is not entirely cleared of rubble — it contains hundreds of rocks, known as the Trojan asteroids, albeit locked in two clumps by the gas giant's gravity.

The property results from the way they form: When a giant star runs out of fuel and can no longer fight against the crushing force of its gravity, its core shrinks to the size of an asteroid, and most of its mass is blasted away in a titanic explosion called a supernova.