NASA’s first mission to return a pattern from an historic asteroid arrived at its goal, the asteroid Bennu, on December three, 2018. This mission, the Origins, Spectral Interpretation, Useful resource Identification, Safety-Regolith Explorer, or OSIRIS-REx, is a seven-year lengthy voyage set to conclude upon the supply to Earth of a minimum of 2.1 ounces (60 grams) and probably as much as virtually 4 and a half kilos (two kilograms) of pattern. It guarantees to be the most important quantity of extraterrestrial materials introduced again from house because the Apollo period.
The 20-year anniversary of the asteroid’s discovery was in September 2019 — and scientists have been amassing information ever since. Right here’s what we already know (and a few of what we hope to seek out out) about this pristine remnant from the early days of our photo voltaic system.
1. It’s Very, Very Darkish…
Bennu is classed as a B-type asteroid, which suggests it incorporates a number of carbon in and together with its varied minerals. Bennu’s carbon content material creates a floor on the asteroid that displays about 4 % of the sunshine that hits it — and that’s not lots. For distinction, the photo voltaic system’s brightest planet, Venus, displays round 65 % of incoming daylight, and Earth displays about 30 %. Bennu is a carbonaceous asteroid that hasn’t undergone drastic, composition-altering change, which means that on and beneath its deeper-than-pitch-black floor are chemical substances and rocks from the beginning of the photo voltaic system.
2. …And Very, Very Previous.
Bennu has been (largely) undisturbed for billions of years. Not solely is it conveniently shut and carbonaceous, additionally it is so primitive that scientists calculated it fashioned within the first 10 million years of our photo voltaic system’s historical past — over four.5 billion years in the past. Due to the Yarkovsky impact — the slight push created when the asteroid absorbs daylight and re-emits that vitality as warmth — and gravitational tugs from different celestial our bodies, it has drifted nearer and nearer to Earth from its possible birthplace: the Major Asteroid Belt between Mars and Jupiter.
three. Bennu Is a “Rubble-Pile” Asteroid — However Don’t Let the Identify Trick You.
Is Bennu house trash or scientific treasure? Whereas “rubble pile” seems like an insult, it’s truly an actual astronomy classification. Rubble-pile asteroids like Bennu are celestial our bodies constructed from plenty of items of rocky particles that gravity compressed collectively. This type of detritus is produced when an affect shatters a a lot bigger physique (for Bennu, it was a mother or father asteroid round 60 miles [about 100 km] broad). Bennu, for distinction, is about as tall because the Empire State Constructing. It possible took only a few weeks for these shards of house wreckage to coalesce into the rubble-pile that’s Bennu. Bennu is filled with holes inside, with 20 to 40 % of its quantity being empty house. The asteroid is definitely at risk of flying aside, if it begins to rotate a lot sooner or interacts too carefully with a planetary physique.
four. Asteroids Could Harbor Hints Concerning the Origin of All Life on Earth…
Bennu is a primordial artifact preserved within the vacuum of house, orbiting amongst planets and moons and asteroids and comets. As a result of it’s so outdated, Bennu may very well be made of fabric containing molecules that had been current when life first fashioned on Earth. All Earth life varieties are primarily based on chains of carbon atoms bonded with oxygen, hydrogen, nitrogen and different components. Nevertheless, natural materials like the type scientists hope to seek out in a pattern from Bennu doesn’t essentially all the time come from biology. It could, although, additional scientists’ search to uncover the function asteroids wealthy in organics performed in catalyzing life on Earth.
5. …However Additionally Platinum and Gold!
Extraterrestrial jewellery sounds nice, and Bennu is more likely to be wealthy in platinum and gold in comparison with the typical crust on Earth. Though most aren’t made virtually completely of stable metallic (however asteroid 16 Psyche could also be!), many asteroids do include components that may very well be used industrially in lieu of Earth’s finite assets. Intently finding out this asteroid will give solutions to questions on whether or not asteroid mining throughout deep-space exploration and journey is possible. Though uncommon metals appeal to essentially the most consideration, water is more likely to be an important useful resource in Bennu. Water (two hydrogen atoms certain to an oxygen atom) can be utilized for ingesting or separated into its elements to get breathable air and rocket gas. Given the excessive value of transporting materials into house, if astronauts can extract water from an asteroid for all times assist and gas, the cosmic past is nearer than ever to being human-accessible.
6. Daylight Can Change the Asteroid’s Total Trajectory.
Gravity isn’t the one issue concerned with Bennu’s future. The facet of Bennu going through the Solar will get warmed by daylight, however a day on Bennu lasts simply four hours and 17.eight minutes, so the a part of the floor that faces the Solar shifts consistently. As Bennu continues to rotate, it expels this warmth, which supplies the asteroid a tiny push in direction of the Solar by about zero.18 miles (roughly zero.29 kilometers) per yr, altering its orbit.
7. There Is a Small Probability That Bennu Will Impression Earth Late within the Subsequent Century.
The NASA-funded Lincoln Close to-Earth Asteroid Analysis group found Bennu in 1999. NASA’s Planetary Protection Coordination Workplace continues to trace near-Earth objects (NEOs), particularly these like Bennu that can come inside about four.6 million miles (7.5 million kilometers) of Earth’s orbit and are labeled as probably hazardous objects. Between the years 2175 and 2199, the prospect that Bennu will affect Earth is just 1-in-2,700, however scientists nonetheless don’t need to flip their backs on the asteroid. Bennu swoops by the photo voltaic system on a path that scientists have confidently predicted, however they’ll refine their predictions with the measurement of the Yarkovsky Impact by OSIRIS-REx and with future observations by astronomers.
eight. Sampling Bennu Will Be Tougher Than We Thought.
Early Earth-based observations of the asteroid steered it had a clean floor with a regolith (the highest layer of free, unconsolidated materials) composed of particles lower than an inch (a few centimeters) massive — at most. Because the OSIRIS-REx spacecraft was capable of take photos with increased decision, it grew to become evident that sampling Bennu can be way more hazardous than what was beforehand believed: new imagery of Bennu’s floor present that it’s largely lined in large boulders, not small rocks. OSIRIS-REx was designed to be navigated inside an space on Bennu of almost 2,000 sq. yards (meters), roughly the dimensions of a car parking zone with 100 areas. Now, it should maneuver to a protected spot on Bennu’s rocky floor inside a constraint of lower than 100 sq. yards, an space of about 5 parking areas.
9. Bennu Was Named After an Historic Egyptian Deity.
Bennu was named in 2013 by a nine-year-old boy from North Carolina who received the Identify that Asteroid! competitors, a collaboration between the mission, the Planetary Society, and the LINEAR asteroid survey that found Bennu. Michael Puzio received the competition by suggesting that the spacecraft’s Contact-and-Go Pattern Mechanism (TAGSAM) arm and photo voltaic panels resemble the neck and wings in illustrations of Bennu, whom historic Egyptians often depicted as a grey heron. Bennu is the traditional Egyptian deity linked with the Solar, creation and rebirth — Puzio additionally famous that Bennu is the residing image of Osiris. The parable of Bennu fits the asteroid itself, on condition that it’s a primitive object that dates again to the creation of the Photo voltaic System. Themes of origins and rebirth are a part of this asteroid’s story. Birds and bird-like creatures are additionally symbolic of rebirth, creation and origins in varied historic myths.
10. Bennu Is Nonetheless Shocking Us!
The spacecraft’s navigation digicam noticed that Bennu was spewing out streams of particles a few occasions every week. Bennu apparently is just not solely a uncommon energetic asteroid (solely a handful of them have been as of but recognized), however probably with Ceres explored by NASA’s Daybreak mission, among the many first of its type that humanity has noticed from a spacecraft. Extra just lately, the mission group found that daylight can crack rocks on Bennu, and that it has items of one other asteroid scattered throughout its floor. Extra items might be added to Bennu’s cosmic puzzle because the mission progresses, and every brings the photo voltaic system’s evolutionary historical past into sharper and sharper focus.
Goddard offers total mission administration, techniques engineering, and the protection and mission assurance for OSIRIS-REx. Dante Lauretta of the College of Arizona, Tucson, is the principal investigator, and the College of Arizona additionally leads the science group and the mission’s science statement planning and information processing. Lockheed Martin House in Denver constructed the spacecraft and is offering flight operations. Goddard and KinetX Aerospace are liable for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall House Flight Middle in Huntsville, Alabama, for the company’s Science Mission Directorate in Washington.