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Frequently asked questions – OSIRIS-REx

The OSIRIS-REx mission

What is OSIRIS-REx?

OSIRIS-REx is the first US-led mission to return a sample from an asteroid to Earth. The mission aims to better explain our solar system's formation and potentially even how life began. By studying asteroid Bennu, scientists will learn more about factors that could influence its path, and the paths of other asteroids like it.

What does OSIRIS-REx stand for?

Origins, Spectral Interpretation, Resource Identification, Security - Regolith Explorer.

What is Canada's role in the OSIRIS-REx mission?

Canada is contributing a laser instrument known as OLA (short for the OSIRIS-REx Laser Altimeter), which is funded by the Canadian Space Agency (CSA). In addition to OLA, Canada is contributing scientific expertise to the OSIRIS-REx mission. The CSA also supports scientists and engineers on OLA's development and operations team, as well as scientists from Canadian institutions who are part of the broader OSIRIS-REx science team. In return for its contributions, Canada will receive a portion of the sample.

When did OSIRIS-REx launch?

OSIRIS-REx was launched on , at 7:05 p.m. ET aboard an Atlas V rocket at the Cape Canaveral Air Force Station, Florida.

What are the main phases of the mission?

The OSIRIS-REx mission will last seven years. Launched in , the OSIRIS-REx spacecraft will reach Bennu, its target asteroid, two years later, in . Scientists will then use five instruments on board to study the asteroid for about a year, mapping its entire surface with centimetre-scale precision. After the sample location is chosen, the spacecraft will approach the surface, and—without landing—extend a robotic arm to collect over 60 g of fine gravel, dust, and small rocks from the asteroid's surface. The sample will be sealed inside a capsule, which will be sent back to Earth, touching down in the Utah desert in . Future generations of scientists will continue to study the sample returned to Earth for decades beyond the mission, though, much like researchers today still study the Moon rocks from the Apollo missions.

When will OSIRIS-REx return?

The OSIRIS-REx spacecraft will leave Bennu in and reach Earth's orbit in . After releasing the sample return capsule to land on Earth, the spacecraft itself will leave to begin a new orbit around the sun, positioned between Earth and Venus.

Is OSIRIS-REx the first mission to return a sample from an asteroid?

No. The first mission to successfully return a sample of an asteroid to Earth was Japan's Hayabusa mission. Launched in , the mission returned a small sample in .

Is OSIRIS-REx the first US mission to visit an asteroid?

No. NASA's first spacecraft to visit an asteroid was the Near Earth Asteroid Rendezvous-Shoemaker spacecraft, which landed on the asteroid Eros on . OSIRIS-REx is Canada's first participation in an asteroid sample-return mission.

How much is the Canadian Space Agency investing in OSIRIS-REx?

The CSA's total investment in OSIRIS-REx for the full life-cycle of the mission is $61 million over 15 years to support the development of OLA and the science team. The instrument was built for the CSA by MDA with significant contributions from subcontractor Optech.

Why won't OSIRIS-REx land on the asteroid? Why will it just obtain a sample without touching down on the surface?

Asteroids are very small compared to planets, and they have very low gravity. This makes it very difficult to land and stay put on their surface. It is more efficient and safe to simply approach the surface and pluck a sample than to actually touch down on the surface.

About Bennu

How did the asteroid Bennu get its name?

In , Michael Puzio, a nine-year-old student in grade three in North Carolina, USA, won an international student contest to give the asteroid a friendlier name. Michael suggested the name because he imagined the spacecraft's robotic arm and solar panels look like the neck and wings of Bennu, the Egyptian deity often depicted as a grey heron.

How big is Bennu?

Bennu is roughly 500 metres in diameter. For comparison, the CN Tower in Toronto, Ontario, is 553 metres high.

Where is asteroid Bennu?

Unlike most asteroids, which are located in the asteroid belt between the orbits of Mars and Jupiter, Bennu travels through space on an elliptical orbit between Venus and Mars.

Why did scientists choose to study Bennu?

Researchers consider Bennu an exciting—and accessible—celestial body. Bennu is one of the 500,000 or so catalogued asteroids and about 9000 Near-Earth Objects. It is classified as a B-type asteroid, and considered to be a rare specimen due to its unusually dark colour. It has changed little since the time of its formation 4 billion years ago, and may reveal a wealth of information about the early Solar System.

About Asteroids

What is an asteroid?

Asteroids are small, rocky bodies in our solar system. They are made up of the remnants of the primitive building blocks that created the terrestrial planets in our solar system. Most of them are located in between the orbits of Mars and Jupiter in a region known as the "asteroid belt."

What's the difference between an asteroid, a comet, a meteor and a meteorite?

Asteroids are composed mainly of rock and metals, while comets are made of ice, dust and small rocks. An object becomes a meteor if it enters Earth's atmosphere. Since meteors leave visible streaks across the sky, they are often known as shooting stars. The term "meteorite" refers to solid debris that survives entry and impact with the ground.

Why should we study asteroids?

To better explain our solar system's formation and how life began, and to increase our understanding of asteroids that could impact Earth.

Asteroids are essentially remnants of the primitive building blocks that created the terrestrial planets in our solar system. Scientists believe that asteroids have not changed very much over the time they were formed, making them cosmic time capsules that can reveal how planets like our own world formed. In addition, asteroids are thought to contain organic molecules like amino acids—the basis for proteins and DNA—leading to speculation that meteorites from asteroids could have seeded the early Earth with the building blocks of life.

Why should Canada study asteroids?

The Canadian landscape is pockmarked with some of the largest meteor impact craters in the world—some of which, like the Manicouagan crater in Quebec, are thought to have been caused by an asteroid.

For decades, scientists in Canada have been studying through telescopes or by recovering fragments of asteroids that have landed on Canadian soil through meteorite impacts. However, meteors that enter our atmosphere are subjected to extreme temperatures, baking away some of the key clues scientists need. Journeying to the asteroid will validate what we have learned though telescopes and meteorites, and help us understand asteroids up close by bringing back a pristine, unaltered sample.

Are asteroids dangerous?

Earth has been hit many times by stray asteroids whose orbit brings them into our vicinity. Sometimes, the effects of these collisions have been spectacular. For example, scientists believe that the dinosaurs disappeared after an asteroid struck Mexico's Yucatan peninsula about 66 million years ago. The impact kicked up massive amounts of dust and debris into the atmosphere, blocking out the Sun's light and causing the Earth's temperature to cool, which led to the extinction of many species.

Most asteroids are located far from Earth in the asteroid belt between Mars and Jupiter, though, and are not dangerous at all. In fact, out of 500,000 known asteroids, only about a thousand are labelled as potentially hazardous.

While asteroids attract attention (and fear) for their impacts, scientists think an asteroid could actually have planted the seeds for all life on Earth. Studying an asteroid will reveal more information about how they form and evolve, as well as how their orbits develop, contributing to our understanding of which asteroids may be hazardous for Earth and better predicting whether or not they may hit our planet.

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