An isolated 3-mile-high (5 km) mountain Ahuna Mons on Ceres is likely volcanic in origin, and the dwarf planet may have a weak, temporary atmosphere. These are just two of many new insights about Ceres from NASA’s Dawn mission published this week in six papers in the journal Science.
“Dawn has revealed that Ceres is a diverse world that clearly had geological activity in its recent past,” said Chris Russell, principal investigator of the Dawn mission, based at the University of California, Los Angeles.
Ahuna Mons is a volcanic dome similar to earthly and lunar volcanic domes but unique in the solar system, according to a new analysis led by Ottaviano Ruesch of NASA’s Goddard Space Flight Center and the Universities Space Research Association. While those on Earth erupt with molten rock, Ceres’ grandest peak likely formed as a salty-mud volcano. Instead of molten rock, salty-mud volcanoes, or “cryovolcanoes,” release frigid, salty water sometimes mixed with mud.
Learn more about Ahuna Mons
“This is the only known example of a cryovolcano that potentially formed from a salty mud mix, and that formed in the geologically recent past,” Ruesch said. Estimates place the mountain formation within the past billion years.
Dawn may also have detected a weak, temporary atmosphere; the probe’s gamma ray and neutron (GRaND) detector observed evidence that Ceres had accelerated electrons from the solar wind to very high energies over a period of about six days. In theory, the interaction between the solar wind’s energetic particles and atmospheric molecules could explain the GRaND observations.
A temporary atmosphere would confirm the water vapor the Herschel Space Observatory detected at Ceres in 2012-2013. The electrons that GRaND detected could have been produced by the solar wind hitting the water molecules that Herschel observed, but scientists are also looking into alternative explanations.
While Ahuna Mons may have erupted liquid water in the not-too-distant past, Dawn found probable water ice right now in the mid-latitude Oxo Crater using its visible and infrared mapping spectrometer (VIR).
Exposed water-ice is rare on the dwarf planet, but the low density of Ceres — 2.08 grams/cm3 vs. 5.5 for Earth — the impact-generated ice detection and the the existence of Ahuna Mons suggest that Ceres’ crust does contain a significant amount of water ice.
Impact craters are clearly the most abundant geological feature on Ceres, and their different shapes help tell the complex story of Ceres’ past. Craters that are roughly polygonal — shapes bounded by straight lines — hint that Ceres’ crust is heavily fractured. In addition, several Cerean craters display fractures on their floors. There are craters with flow-like features. Bright areas are peppered across Ceres, with the most reflective ones in Occator Crater. Some crater shapes could indicate water-ice in the subsurface.
All these crater forms imply an outer shell for Ceres that is not purely ice or rock, but rather a mixture of both. Scientists also calculated the ratio of various craters’ depths to diameters, and found that some amount of crater relaxation must have occurred as icy walls gradually slump.
“The uneven distribution of craters indicates that the crust is not uniform, and that Ceres has gone through a complex geological evolution,” Hiesinger said.
Ceres’ crust also appears loaded with clay-forming minerals called phyllosilicates. These phyllosilicates are rich in magnesium and also have some ammonium embedded in their crystalline structure. Their distribution throughout the dwarf planet’s crust indicates Ceres’ surface material has been altered by a global process involving water.
Now in its extended mission, the Dawn spacecraft has been increasing its altitude since Sept. 2 as scientists stand back once again for a broader look at Ceres under different lighting conditions now compared to earlier in the mission.
KENNEDY SPACE CENTER, FL – Bound for Bennu, NASA’s OSIRIS-REx robotic explorer began a trailblazing 7 year round trip sampling sortie on Sept. 8 in search of the origin of life with a spectacular sky show – thrilling spectators ringing the Florida Space Coast.
Hordes of space enthusiasts from all across the globe descended on the Kennedy Space Center and Cape Canaveral region for the chance of a lifetime to witness a once in a lifetime liftoff to the carbon rich asteroid – which could potentially bring back samples infused with the organic chemicals like amino acids that are the building blocks of life as we know it.
NASA’s Origins, Spectral Interpretation, Resource Identification, Security – Regolith Explorer (OSIRIS-REx) spacecraft departed Earth with an on time engine ignition of a United Launch Alliance Atlas V rocket under crystal clear skies on Thursday, September 8 at 7:05 p.m. EDT from Space Launch Complex 41 at Cape Canaveral Air Force Station.
Everything went exactly according to plan for the daring mission bolding seeking to gather rocks and soil from Bennu – using an ingenious robotic arm named TAGSAM – and bring at least a 60-gram (2.1-ounce) sample back to Earth in 2023 for study by scientists using the world’s most advanced research instruments.
“We got everything just exactly perfect,” said Dante Lauretta, the principal investigator for OSIRIS-REx at the University of Arizona, at the post launch briefing at the Kennedy Space Center. “We hit all our milestone within seconds of predicts.
The space rock measures about the size of a small mountain at about a third of a mile in diameter.
And the picture perfect near sunset launch rewarded photographers from near and far with a spectacular series of richly hued photo and video recordings.
So I’ve gathered here a variety of launch imagery from multiple vantage points shot by friends, colleagues and myself – for the enjoyment of readers of Universe Today and Beyond!
As you’ll see and hear the ULA Atlas V rocket integrated with OSIRIS-Rex on top thundered off the Cape’s pad 41 and shot skyward straight up along an equatorial path into Florida’s sun.
From every vantage point the rocket and its ever expanding vapor trail were visible for some 4 or 5 minutes or more. From my location on the roof of NASA’s Vehicle Assembly Building (VAB) the rocket finally arched over nearly straight above us and the sun produced a magnificent thin and nearly straight shadow of the vapor trail on the ground running out to the Atlantic Ocean towards Africa.
It was truly an unforgettable sight to behold. And folks at Playalinda Beach, the best public viewing spot just a few miles north of pad 40 had an uninhibited view of the rocket to the base of the pad – while they waded and swam in the oceans waters with waves crashing on shore as the Atlas rocket blasted to space.
OSIRIS-REx separated as planned from the Atlas V rockets liquid oxygen and liquid hydrogen fueled second stage rocket to fly free at 8:04 p.m. on Sept. 8 – 55 minutes after launch.
The pair of solar arrays deployed as planned to provide the probes life giving power.
The spacecraft was built by prime contractor Lockheed.
“The spacecraft is healthy and functioning properly,” Richard Kuhns, Lockheed Martin OSIRIS-REx program manager, told me in an interview at the post-launch briefing.
“The primary objective of the OSIRIS-Rex mission is to bring back pristine material from the surface of the carbonaceous asteroid Bennu, OSIRIS-Rex Principal Investigator Dante Lauretta told Universe Today in a prelaunch interview in the KSC cleanroom with the spacecraft as the probe was undergoing final preparations for shipment to the launch pad.
“We are interested in that material because it is a time capsule from the earliest stages of solar system formation.”
“It records the very first material that formed from the earliest stages of solar system formation. And we are really interested in the evolution of carbon during that phase. Particularly the key prebiotic molecules like amino acids, nucleic acids, phosphates and sugars that build up. These are basically the biomolecules for all of life.”
The asteroid is 1,614-foot (500 m) in diameter and crosses Earth’s orbit around the sun every six years.
After a two year flight through space, including an Earth swing by for a gravity assisted speed boost in 2017, OSIRIS-REx will reach Bennu in Fall 2018 to begin about 2 years of study in orbit to determine the physical and chemical properties of the asteroid in extremely high resolution.
While orbiting Bennu starting in 2018 it will move in close to explore the asteroid for about two years with its suite of science instruments, scanning in visible and infrared light. After a thorough site selection, it will move carefully towards the surface and extend the 11 foot long TAGSAM robotic arm and snatch pristine soil samples containing organic materials from the surface using the TAGSAM collection dish over just 3 to 5 seconds.
Once a good sample collection is confirmed, the dish will then be placed inside the Earth return canister and be brought back to Earth for study by researchers using all of the most sophisticated science instruments available to humankind.
Using the 11 foot long TAGSAM robotic arm that functions somewhat like a pogo stick, OSIRIS-REx will gather rocks and soil and bring at least a 60-gram (2.1-ounce) sample back to Earth on Sept 24, 2023. It has the capacity to scoop up to about 2 kg or more.
The two stage ULA Atlas V performed flawlessly and delivered OSIRIS-Rex into a hyperbolic trajectory away from Earth.
The 189 foot tall ULA Atlas V rocket launched in the rare 411 configuration for only the 3rd time on this mission – which is the 65th for the Atlas V.
The Atlas 411 vehicle includes a 4-meter diameter large Payload Fairing (PLF) and one solid rocket booster that augments the first stage. The Atlas booster for this mission is powered by the RD AMROSS RD-180 engine and the Centaur upper stage was powered by the Aerojet Rocketdyne RL10A.
The RD-180 burns RP-1 (Rocket Propellant-1 or highly purified kerosene) and liquid oxygen and delivers 860,200 lb of thrust at sea level.
The strap on solid delivers approximately 348,500 pounds of thrust.
The Centaur delivers 22, 230 lbf of thrust and burns liquid oxygen and liquid hydrogen.
The solid was jettisoned at 139 seconds after liftoff.
This is ULA’s eighth launch in 2016 and the 111th successful launch since the company was formed in December 2006.
OSIRIS-REx will return the largest sample from space since the American and Soviet Union’s moon landing missions of the 1970s.
Watch these pair of up close videos (from myself and Jeff Seibert) captured directly at the pad with the sights and sounds of the fury of launch:
Video Caption: ULA Atlas V rocket lifts off on September 8, 2016 from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s OSIRIS-REx asteroid sampling spacecraft, in this remote camera view taken from inside the launch pad perimeter. Credit: Ken Kremer/kenkremer.com
Video Caption: Compilation of my launch videos from the ULA Atlas 5 launch in support of the NASA OSIRIS_REx asteroid sample return mission to the asteroid Bennu (#101955). It was launched on September 8th, 2016 from Pad 41 of CCAFS. It is scheduled to land in UTAH with asteroid samples on September 24, 2023. Credit: Jeff Seibert
OSIRIS-REx is the third mission in NASA’s New Frontiers Program, following New Horizons to Pluto and Juno to Jupiter, which also launched on Atlas V rockets.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is responsible for overall mission management.
OSIRIS-REx complements NASA’s Asteroid Initiative – including the Asteroid Redirect Mission (ARM) which is a robotic spacecraft mission aimed at capturing a surface boulder from a different near-Earth asteroid and moving it into a stable lunar orbit for eventual up close sample collection by astronauts launched in NASA’s new Orion spacecraft. Orion will launch atop NASA’s new SLS heavy lift booster concurrently under development.
Watch for Ken’s continuing OSIRIS-REx mission and launch reporting from on site at the Kennedy Space Center and Cape Canaveral Air Force Station, FL.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
The Earth departure for NASA’s Origins, Spectral Interpretation, Resource Identification, Security – Regolith Explorer (OSIRIS-REx) spacecraft began with an on time engine ignition from Space Launch Complex 41 at Cape Canaveral Air Force Station on a United Launch Alliance Atlas V rocket shortly before a crystal clear sunset this evening, Thursday, September 8 at 7:05 p.m. EDT.
The Atlas V rocket with OSIRIS-Rex bolted on top roared off launch pad 41 and shot straight up into the sun drenched skies of the sunshine state.
The launch wowed hordes of excited spectators who gathered from near and far to witness America’s first mission to gather pristine samples of soil and rock from Bennu’s coal black and carbon rich surface – and eventually return them to Earth for analysis using the most powerful science instruments humankind has invented.
“This represents the hopes and dreams and blood, sweat and tears of thousands of people who have been working on this for years,” said Dante Lauretta, the principal investigator for OSIRIS-REx at the University of Arizona.
“I can’t tell you how thrilled I was this evening, thinking of the people who played a part in this.”
OSIRIS-Rex is on a totally unique 4.5 billion mile roundtrip mission to unlock the mysteries of the formation of our Solar System 4.5 Billion years ago and ourselves as Earth evolved over time.
“Today, we celebrate a huge milestone for this remarkable mission, and for this mission team,” said NASA Administrator Charles Bolden, in a statement.
“We’re very excited about what this mission can tell us about the origin of our solar system, and we celebrate the bigger picture of science that is helping us make discoveries and accomplish milestones that might have been science fiction yesterday, but are science facts today.”
101955 Bennu is a near Earth asteroid discovered in 1999. It was selected specifically as the sampling because it is a carbon-rich asteroid.
It will take about 2 years for OSIRIS-Rex to reach Bennu in 2018 following a flyby of Earth in 2017.
While orbiting Bennu starting in 2018 it will move in close explore Bennu for about two years with its suite of science instruments. After a thorough site selection, it will move carefully towards the surface and extend the 11 foot long TAGSAM robotic arm and snatch pristine soil samples containing organic materials from the surface using the TAGSAM collection dish. The dish will then be placed inside the Earth return canister and be brought back to Earth for study by researchers using all of the most sophisticated science instruments available to humankind.
The asteroid is 1,614-foot (500 m) in diameter and crosses Earth’s orbit around the sun every six years.
Using the 11 foot long TAGSAM robotic arm that functions somewhat like a pogo stick, OSIRIS-REx will gather rocks and soil and bring at least a 60-gram (2.1-ounce) sample back to Earth in 2023. It has the capacity to scoop up to about 2 kg or more.
The two stage ULA Atlas V performed flawlessly and delivered OSIRIS-Rex into a hyperbolic trajectory away from Earth.
The 189 foot tall ULA Atlas V rocket launched in the rare 411 configuration for only the 3rd time on this mission – which is the 65th for the Atlas V.
The Atlas 411 vehicle includes a 4-meter diameter large Payload Fairing (PLF) and one solid rocket booster that augments the first stage. The Atlas booster for this mission is powered by the RD AMROSS RD-180 engine and the Centaur upper stage was powered by the Aerojet Rocketdyne RL10A.
The RD-180 burns RP-1 (Rocket Propellant-1 or highly purified kerosene) and liquid oxygen and delivers 860,200 lb of thrust at sea level.
The strap on solid delivers approximately 348,500 pounds of thrust.
The Centaur delivers 22,230 lbf of thrust and burns liquid oxygen and liquid hydrogen.
The solid was jettisoned at 139 seconds after liftoff.
This is ULA’s eighth launch in 2016 and the 111th successful launch since the company was formed in December 2006.
OSIRIS-REx will return the largest sample from space since the American and Soviet Union’s moon landing missions of the 1970s.
OSIRIS-REx is the third mission in NASA’s New Frontiers Program, following New Horizons to Pluto and Juno to Jupiter, which also launched on Atlas V rockets.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is responsible for overall mission management.
OSIRIS-REx complements NASA’s Asteroid Initiative – including the Asteroid Redirect Mission (ARM) which is a robotic spacecraft mission aimed at capturing a surface boulder from a different near-Earth asteroid and moving it into a stable lunar orbit for eventual up close sample collection by astronauts launched in NASA’s new Orion spacecraft. Orion will launch atop NASA’s new SLS heavy lift booster concurrently under development.
Watch for Ken’s continuing OSIRIS-REx mission and launch reporting from on site at the Kennedy Space Center and Cape Canaveral Air Force Station, FL.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
KENNEDY SPACE CENTER, FL – Today is ‘Earth Departure Day’ for OSIRIS-REx, NASA’s first mission to snatch “pristine materials” from the surface of a near Earth asteroid named Bennu and deliver them back to Earth in seven years on a mission to unlock mysteries on the formation of our Solar System and ourselves 4.5 Billion years ago.
The 4.5 Billion mile roundtrip ‘Journey to Bennu and Back’ begins today. All systems are GO for a spectacular dinner-time blastoff of NASAs OSIRIS-REx spacecraft from the Florida Space Coast.
Earth departure for NASA’s Origins, Spectral Interpretation, Resource Identification, Security – Regolith Explorer (OSIRIS-REx) spacecraft from Space Launch Complex 41 at Cape Canaveral Air Force Station on a United Launch Alliance Atlas V rocket is slated for shortly before sunset this evening, Thursday, September 8 at 7:05 p.m. EDT.
Excited spectators are filling local area hotels for this once in a lifetime mission to ‘Bennu and Back.’
Bennu is a small, carbon-rich asteroid – meaning it contains significant amounts of organic molecules, the stuff of which life is made.
Bennu is only about a third of mile in diameter, measuring 500 meters or 1,614 feet across and it crosses Earth’s orbit around the sun every six years.
You can watch the sure to be a spectacular launch live in person here in sunny Florida or live via a choice of webcasts.
NASA’s OSIRIS-REx launch coverage will be broadcast on NASA TV beginning at 4:30 p.m. EDT Sept. 8, as well as on a ULA webcast.
You can watch the launch live at NASA TV at – http://www.nasa.gov/nasatv
You can watch the launch live at ULA at – www.ulalaunch.com
Today’s weather forecast remains very promising and is currently 80% GO for favorable conditions. The only concern is for cumulus clouds.
There are 3 opportunities in a row to launch OSIRIS-Rex.
In case of a delay 24 or 48 hour delay, the forecast drops only slightly to 70% GO.
The United Launch Alliance Atlas V rocket and OSIRIS-REx spacecraft were rolled out some 1800 feet from the Vertical Integration Facility (VIF) – where the rocket is assembled- to launch pad 41 starting at about 9 a.m. yesterday morning September 7, 2018.
Watch this OSIRIS-Rex trailer from NASA Goddard illustrating the probes Earth departure launch phase:
NASAs OSIRIS-REx spacecraft is on a mission to explore asteroid Bennu and return a sample to Earth. The OSIRIS-REx launch window opens on September 8, 2016, when the spacecraft begins its two-year journey to Bennu aboard an Atlas V rocket at Cape Canaveral, Florida. After arriving at Bennu in 2018, OSIRIS-REx will spend over a year exploring the asteroid before approaching its surface to grab a sample. This pristine material, formed at the dawn of the solar system, will be returned to Earth in 2023, providing clues to Bennus origins and our own. Credit: NASA’s Goddard Space Flight Center/David Ladd
OSIRIS-REx will gather rocks and soil and bring at least a 60-gram (2.1-ounce) sample back to Earth in 2023. It has the capacity to scoop up to about 2 kg or more.
The mission will help scientists investigate how planets formed and how life began. It will also improve our understanding of asteroids that could impact Earth by measuring the Yarkovsky effect.
Bennu is an unchanged remnant from the collapse of the solar nebula and birth of our solar system some 4.5 billion years ago.
It was chosen as the target because it is little altered over time and thus ‘pristine’ in nature.
Bennu is a near-Earth asteroid and was selected for the sample return mission because it could hold clues to the origin of the solar system and host organic molecules that may have seeded life on Earth.
The 189 foot tall ULA Atlas V rocket is launching in the rare 411 configuration for only the 3rd time on this mission – which is the 65th for the Atlas V.
The Atlas 411 vehicle includes a 4-meter diameter payload fairing and one solid rocket booster that augments the first stage. The Atlas booster for this mission is powered by the RD AMROSS RD-180 engine and the Centaur upper stage was powered by the Aerojet Rocketdyne RL10C-1 engine.
The RD-180 burns RP-1 (Rocket Propellant-1 or highly purified kerosene) and liquid oxygen and delivers 860,200 lb of thrust at sea level.
The strap on solids deliver approximately 500,000 pounds of thrust.
The solids will be jettisoned about 2 minutes after liftoff.
OSIRIS-REx will return the largest sample from space since the American and Soviet Union’s moon landing missions of the 1970s.
OSIRIS-REx is the third mission in NASA’s New Frontiers Program, following New Horizons to Pluto and Juno to Jupiter, which also launched on Atlas V rockets.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is responsible for overall mission management.
OSIRIS-REx complements NASA’s Asteroid Initiative – including the Asteroid Redirect Mission (ARM) which is a robotic spacecraft mission aimed at capturing a surface boulder from a different near-Earth asteroid and moving it into a stable lunar orbit for eventual up close sample collection by astronauts launched in NASA’s new Orion spacecraft. Orion will launch atop NASA’s new SLS heavy lift booster concurrently under development.
Watch for Ken’s continuing OSIRIS-REx mission and launch reporting from on site at the Kennedy Space Center and Cape Canaveral Ait Force Station, FL.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Learn more about OSIRIS-REx, InSight Mars lander, SpaceX missions, Juno at Jupiter, SpaceX CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:
Sep 8-9: “OSIRIS-REx lainch, SpaceX missions/launches to ISS on CRS-9, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
As NASA prepares to send a spacecraft to a distant asteroid, another space rock made a surprise visit to Earth’s vicinity. The newly discovered small asteroid, named 2016 RB1, passed safely by Earth, coming within approximately 23,900 miles (38,463 km) of our planet, or just outside the orbit of many communications satellites.
The asteroid passed by Earth at 1:28 p.m. Eastern Time (1728 UT).
Click on the image if it is not animating in your browser.
The asteroid was discovered on Monday, September 5 by the Mt. Lemmon Survey telescope in Tucson, Arizona. 2016 RB1 is estimated to be between 24 to 52 feet (7.3 – 16 meters) across, which is just a bit smaller than the Chelyabinsk meteor that exploded over northern Russian in February 2013, which was estimated to be around 56 ft (17 meters) wide.
On Thursday, September 8, NASA hopes to launch its OSIRIS-ReX mission to study asteroid Bennu and conduct a sample return, with the sample coming back to Earth by 2023. With the mission, scientists hope to learn more about the formation and evolution asteroids and of the Solar System as a whole.
Here’s a graphic comparing the small asteroid 2016 RB1 to other objects, compiled by Mikko Tuomela and Massimo Orgiazzi.
2016 RB1 is the third asteroid so far in September 2016 that traveled between the Earth and the Moon. Asteroid 2016 RR1 passed by at 0.32 lunar distances on September 2, and just a few hours later, asteroid 2016 RS1 passed by at 0.48 times the Earth-moon distance. But this latest asteroid pass is the closest, at 0.10 lunar distances.
From its orbit, astronomers have determined 2016 RB1 is likely an Aten asteroid, a group of Near-Earth Objects that cross the orbits of Earth, Venus and even Mercury.
KENNEDY SPACE CENTER, FL – OSIRIS-Rex, NASA’s first mission to retrieve and return samples of “pristine materials” from the surface of an asteroid and return them to Earth for high powered analysis by the world’s most advanced science instruments is encapsulated in the nose cone that’s bolted atop its Atlas rocket that has just been rolled out to its Earth departure launch pad.
It’s a groundbreaking mission that could inform us about astrobiology and yield significant clues to help determine the ‘Origin of Life’ on Earth.
NASA’s Origins, Spectral Interpretation, Resource Identification, Security – Regolith Explorer (OSIRIS-REx) spacecraft will launch from Space Launch Complex 41 at Cape Canaveral Air Force Station on a United Launch Alliance Atlas V rocket on September 8 at 7:05 p.m. EDT.
The United Launch Alliance Atlas V rocket and OSIRIS-REx spacecraft were moved about 1800 feet from the Vertical Integration Facility (VIF) – where the rocket is assembled- to launch pad 41 starting at about 9 a.m. this morning September 7, 2018.
Watch this Atlas V rocket roll video:
The ULA, NASA and science team conducted a launch readiness review yesterday and gave the GO for launch with all systems passing the stringent rocket and safety review. The even search for signs of any debris from last week’s SpaceX Falcon 9 explosion at the adjacent pad 40 located about a mile south. No signs of any debris or damage were found at pad 40 or the rocket and spacecraft.
The weather forecast is currently 80% GO for favorable conditions. The only concern is for cumulus clouds.
There are 3 opportunities in a row to launch OSIRIS-Rex.
In case of a delay 24 or 48 hour delay, the forecast drops only slightly to 70% GO.
OSIRIS-REx goal is to fly on a roundtrip seven-year journey of some 4.5 billion miles to the near-Earth asteroid target named Bennu and back.
Watch this mission video:
Video Caption: This video describes the seven-year journey of NASA’s OSIRIS-Rex mission from launch and cruising through space to asteroid Bennu and back. The probe will study Bennu, grab a 2 ounce or more sample from the surface and bring it back to Earth for lab study by researchers. Credit: Lockheed Martin/NASA
101955 Bennu is a near Earth asteroid discovered in 1999. It was selected specifically because it is a carbon-rich asteroid.
While orbiting Bennu starting in 2018 it will move in close and snatch pristine soil samples containing organic materials from the surface using the TAGSAM collection dish, and bring them back to Earth for study by researchers using all of the most sophisticated science instruments available to humankind.
The asteroid is 1,614-foot (500 m) in diameter and crosses Earth’s orbit around the sun every six years.
“The primary objective of the OSIRIS-Rex mission is to bring back pristine material from the surface of the carbonaceous asteroid Bennu, OSIRIS-Rex Principal Investigator Dante Lauretta told Universe Today in the PHSF, as the probe was undergoing final preparation for shipment to the launch pad.
“It records the very first material that formed from the earliest stages of solar system formation. And we are really interested in the evolution of carbon during that phase. Particularly the key prebiotic molecules like amino acids, nucleic acids, phosphates and sugars that build up. These are basically the biomolecules for all of life.”
OSIRIS-REx will gather rocks and soil and bring at least a 60-gram (2.1-ounce) sample back to Earth in 2023. It has the capacity to scoop up to about 1 kg or more.
The mission will help scientists investigate how planets formed and how life began. It will also improve our understanding of asteroids that could impact Earth by measuring the Yarkovsky effect.
I asked Lauretta to explain in more detail why was Bennu selected as the target to answer fundamental questions related to the origin of life ?
“We selected asteroid Bennu as the target for this mission because we feel it has the best chance of containing those pristine organic compounds from the early stage of solar system formation,” Lauretta told me.
And that information is based on our ground based spectral characterization using telescopes here on Earth. Also, space based assets like the Hubble Space Telescope and the Spitzer Space Telescope.
What is known about the presence of nitrogen containing compounds like amino acids and other elements on Bennu that are the building blocks of life?
“When we look at the compounds that make up these organic materials in these primitive asteroidal materials, we see a lot of carbon,” Lauretta explained.
“But we also see nitrogen, oxygen, hydrogen, sulfur and phosphorous. We call those the CHONPS. Those are the six elements we really focus on when we look at astrobiology and prebiotic chemistry and how those got into the origin of life.”
The OSIRIS-REx spacecraft was built for NASA by prime contractor Lockheed Martin at their facility near Denver, Colorado and flown to the Kennedy Space Center on May 20.
It will map the chemistry and mineralogy of the primitive carbonaceous asteroid. The team will initially select about 10 target areas for further scrutiny as the sampling target. This will be whittled down to two, a primary and backup, Enos told me.
After analyzing the data returned, the science team then will select a site where the spacecraft’s robotic sampling arm will grab a sample of regolith and rocks. The regolith may record the earliest history of our solar system.
Engineers will command the spacecraft to gradually move on closer to the chosen sample site, and then extend the arm to snatch the pristine samples with the TAGSAM sample return arm.
PI Lauretta will make the final decision on when and which site to grab the sample from.
“As the Principal Investigator for the mission I have responsibility for all of the key decisions during our operations,” Lauretta replied. “So we will be deciding on where we want to target our high resolution investigations for sample site evaluation. And ultimately what is the one location we want to send the spacecraft down to the surface of the asteroid to and collect that sample.”
“And then we have to decide like if we collected enough sample and are we ready to stow it in the sample return capsule. Or are we going to use one of our 2 contingency bottles of gas to go for a second attempt.”
“The primary objective is one successful sampling event. So when we collect 60 grams or 2 ounces of sample then we are done!”
“In the event that we decide to collect more, it will be intermixed with anything we collected on the first attempt.”
The priceless sample will then be stowed in the on board sample return capsule for the long journey back to Earth.
Bennu is an unchanged remnant from the collapse of the solar nebula and birth of our solar system some 4.5 billion years ago, little altered over time.
Bennu is a near-Earth asteroid and was selected for the sample return mission because it could hold clues to the origin of the solar system and host organic molecules that may have seeded life on Earth.
OSIRIS-REx will return the largest sample from space since the American and Soviet Union’s moon landing missions of the 1970s.
OSIRIS-REx is the third mission in NASA’s New Frontiers Program, following New Horizons to Pluto and Juno to Jupiter, which also launched on Atlas V rockets.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is responsible for overall mission management.
OSIRIS-REx complements NASA’s Asteroid Initiative – including the Asteroid Redirect Mission (ARM) which is a robotic spacecraft mission aimed at capturing a surface boulder from a different near-Earth asteroid and moving it into a stable lunar orbit for eventual up close sample collection by astronauts launched in NASA’s new Orion spacecraft. Orion will launch atop NASA’s new SLS heavy lift booster concurrently under development.
Watch for Ken’s continuing OSIRIS-REx mission and launch reporting from on site at the Kennedy Space Center and Cape Canaveral Ait Force Station, FL.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Learn more about OSIRIS-REx, InSight Mars lander, SpaceX missions, Juno at Jupiter, SpaceX CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:
Sep 7-9: “OSIRIS-REx lainch, SpaceX missions/launches to ISS on CRS-9, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
Freddie Mercury, the frontman from the rock band Queen, is getting his name etched in the night sky. No, they’re not naming another planet after him. That would be confusing. Instead, an asteroid will bear the name of the iconic singer.
If you don’t know much about the band Queen, there’s a connection between them and astronomy. Brian May, the band’s guitarist, holds a PhD. in astrophysics. He studied reflected light from interplanetary dust and the velocity of dust in the plane of the Solar System. But when Queen became mega-popular in the 70’s, he abandoned astrophysics, for the most part.
Brian May is still involved with space, and has an interest in asteroids. He helped the ESA launch Asteroid Day in June 2016, to raise awareness of the threat that asteroids pose to Earth. So there’s the connection.
As for the asteroid that will bear Freddie Mercury’s name, it was previously named Asteroid 17473, but will now be known as Asteroid FreddieMercury 17473. It’s a rock about 3.5 km in diameter in the asteroid belt between Mars and Jupiter.
Today would have been Freddie’s 70th birthday, if he were still alive. So this naming is a fitting commemorative gesture. According to the International Astronomical Union, who handles the naming of objects in space, the naming of the asteroid is in honour of “Freddie’s outstanding influence in the world.”
Brian May explains things in this video:
We’re mostly science-minded people, so you may be skeptical of Freddie’s influence in the world. He was no scientist, that’s for sure. But if you lived through Queen’s heyday, as I did, you can sort of see it.
Freddie Mercury was a very polished entertainer, with a great voice and fantastic stage presence. He mastered the theatrical side of performing as a rock frontman, and his voice spanned four octaves. The music he made with his band-members in Queen was very original. Mercury was a creative force, that’s for sure.
Check out “Killer Queen” from 1974.
Plus, William Shatner (aka Captain James Tiberius Kirk) clearly had a warm spot in his heart for Freddie and the rest of Queen. How else to explain his version of Queen’s timeless tune “Bohemian Rhapsody?”
If that isn’t a ringing endorsement of Freddie Mercury and Queen, I don’t know what is.
The asteroid that will bear Freddie Mercury’s name was discovered by Belgian astronomer Henri Debehogne in 1991. It travels an elliptical path around the Sun, and never comes closer than 350 million km to Earth. It isn’t very reflective, so only powerful telescopes can see it. But there it’ll be, for anyone with a powerful enough telescope to look with, as long as human civilization lasts.
Freddie Mercury isn’t the first entertainer to have something in space bear his name. In fact, he’s not even the first member of Queen to have that honor. An asteroid first seen in 1998 now bears the name Asteroid 52665 Brianmay, in honor of the guitarist from Queen.
Other musicians and singers who’ve had space rocks named after them include the Beatles, Enya, Frank Zappa, David Bowie, Aretha Franklin, Yes, and Bruce Springsteen. Authors Kurt Vonnegut, Vladimir Nabokov, and Douglas Adams and the characters Don Quixote, James Bond, Sherlock Holmes and Dr Watson also have the honor.
As for the rock itself, Oxford astrophysics professor Chris Lintott told the Guardian, “I think it’s wonderful to name an asteroid after Freddie Mercury. Pleasingly, it’s on a slightly eccentric orbit about the sun, just as the man himself was.”
Freddie died in 1991 from complications from AIDS, but his music still lives on. Maybe Asteroid FreddieMercury 17473 will help us remember him.
KENNEDY SPACE CENTER, FL – OSIRIS-Rex, the first American sponsored probe aimed at retrieving “pristine materials” from the surface of an asteroid and returning them to Earth has been fully assembled at its Florida launch base and is ready to blastoff ten days from today on Sep. 8. It’s a groundbreaking mission that could inform us about astrobiology and the ‘Origin of Life.’
“We are interested in that material because it is a time capsule from the earliest stages of solar system formation,” said Dante Lauretta, principal investigator for OSIRIS-REx at the University of Arizona, Tucson, in an interview with Universe Today beside the completed spacecraft inside the Payloads Hazardous Servicing Facility, or PHSF, clean room processing facility at NASA’s Kennedy Space Center in Florida.
With virtually all prelaunch processing complete, leading members of the science, engineering and launch team including Lauretta met with several members of the media, including Universe Today, inside the clean room for a last and exclusive up-close look and briefing with the one-of-its-kind $800 million Asteroid sampling probe last week.
OSIRIS-REx goal is to fly on a roundtrip seven-year journey to the near-Earth asteroid target named Bennu and back. 101955 Bennu is a near Earth asteroid and was selected specifically because it is a carbon-rich asteroid.
While orbiting Bennu it will move in close and snatch pristine soil samples containing organic materials from the surface using the TAGSAM collection dish, and bring them back to Earth for study by researchers using all of the most sophisticated science instruments available to humankind.
“The primary objective of the OSIRIS-Rex mission is to bring back pristine material from the surface of the carbonaceous asteroid Bennu, OSIRIS-Rex Principal Investigator Dante Lauretta told Universe Today in the PHSF, as the probe was undergoing final preparation for shipment to the launch pad.
“It records the very first material that formed from the earliest stages of solar system formation. And we are really interested in the evolution of carbon during that phase. Particularly the key prebiotic molecules like amino acids, nucleic acids, phosphates and sugars that build up. These are basically the biomolecules for all of life.”
OSIRIS-REx will gather rocks and soil and bring at least a 60-gram (2.1-ounce) sample back to Earth in 2023. It has the capacity to scoop up to about 1 kg or more.
The mission will help scientists investigate how planets formed and how life began. It will also improve our understanding of asteroids that could impact Earth by measuring the Yarkovsky effect.
I asked Lauretta to explain in more detail why was Bennu selected as the target to answer fundamental questions related to the origin of life?
“We selected asteroid Bennu as the target for this mission because we feel it has the best chance of containing those pristine organic compounds from the early stage of solar system formation,” Lauretta told me.
“And that information is based on our ground based spectral characterization using telescopes here on Earth. Also, space based assets like the Hubble Space Telescope and the Spitzer Space Telescope.”
What is known about the presence of nitrogen containing compounds like amino acids and other elements on Bennu that are the building blocks of life?
“When we look at the compounds that make up these organic materials in these primitive asteroidal materials, we see a lot of carbon,” Lauretta explained.
“But we also see nitrogen, oxygen, hydrogen, sulfur and phosphorous. We call those the CHONPS. Those are the six elements we really focus on when we look at astrobiology and prebiotic chemistry and how those got into the origin of life.”
The OSIRIS-REx spacecraft was built for NASA by prime contractor Lockheed Martin at their facility near Denver, Colorado and flown to the Kennedy Space Center on May 20.
For the past three months it has undergone final integration, processing and testing inside the PHSF under extremely strict contamination control protocols to prevent contamination by particle, aerosols and most importantly organic residues like amino acids that could confuse researchers seeking to discover those very materials in the regolith samples gathered for return to Earth.
The PHFS clean room was most recently used to process the Orbital ATK Cygnus space station resupply vehicles. It has also processed NASA interplanetary probes such as the Curiosity Mars Science Laboratory and MAVEN Mars orbiter missions.
The spacecraft will reach Bennu in 2018. Once within three miles (5 km) of the asteroid, the spacecraft will begin at least six months of comprehensive surface mapping of the carbonaceous asteroid, according to Heather Enos, deputy principal investigator, in an interview with Universe Today.
“We will then move the spacecraft to within about a half kilometer or so to collect further data,” Enos elaborated.
It will map the chemistry and mineralogy of the primitive carbonaceous asteroid. The team will initially select about 10 target areas for further scrutiny as the sampling target. This will be whittled down to two, a primary and backup, Enos told me.
After analyzing the data returned, the science team then will select a site where the spacecraft’s robotic sampling arm will grab a sample of regolith and rocks. The regolith may record the earliest history of our solar system.
Engineers will command the spacecraft to gradually move on closer to the chosen sample site, and then extend the arm to snatch the pristine samples the TAGSAM sample return arm.
PI Lauretta will make the final decision on when and which site to grab the sample from.
“As the Principal Investigator for the mission I have responsibility for all of the key decisions during our operations,” Lauretta replied. “So we will be deciding on where we want to target our high resolution investigations for sample site evaluation. And ultimately what is the one location we want to send the spacecraft down to the surface of the asteroid to and collect that sample.”
“And then we have to decide like if we collected enough sample and are we ready to stow it in the sample return capsule. Or are we going to use one of our 2 contingency bottles of gas to go for a second attempt.”
“The primary objective is one successful sampling event. So when we collect 60 grams or 2 ounces of sample then we are done!”
“In the event that we decide to collect more, it will be intermixed with anything we collected on the first attempt.”
The priceless sample will then be stowed in the on board sample return capsule for the long journey back to Earth.
Bennu is an unchanged remnant from the collapse of the solar nebula and birth of our solar system some 4.5 billion years ago, little altered over time.
Bennu is a near-Earth asteroid and was selected for the sample return mission because it could hold clues to the origin of the solar system and host organic molecules that may have seeded life on Earth.
OSIRIS-REx will return the largest sample from space since the American and Soviet Union’s moon landing missions of the 1970s.
Watch this USLaunchReport video shot during media visit inside the PHSF on Aug. 20, 2016:
Video caption: Our first introduction to the OSIRIS-REx asteroid bound mission in search of the origins of life, from inside the Payloads Hazardous Servicing Facility at NASA’s Kennedy Space Center on Aug. 20, 2016. Credit: USLaunchReport
OSIRIS-REx is the third mission in NASA’s New Frontiers Program, following New Horizons to Pluto and Juno to Jupiter, which also launched on Atlas V rockets.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is responsible for overall mission management.
OSIRIS-REx complements NASA’s Asteroid Initiative – including the Asteroid Redirect Mission (ARM) which is a robotic spacecraft mission aimed at capturing a surface boulder from a different near-Earth asteroid and moving it into a stable lunar orbit for eventual up close sample collection by astronauts launched in NASA’s new Orion spacecraft. Orion will launch atop NASA’s new SLS heavy lift booster concurrently under development.
Watch for Ken’s continuing OSIRIS-REx mission and launch reporting from on site at the Kennedy Space Center and Cape Canaveral Ait Force Station, FL.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Between the orbits of Mars and Jupiter lies the Solar System’s Main Asteroid Belt. Consisting of millions of objects that range in size from hundreds of kilometers in diameter (like Ceres and Vesta) to one kilometer or more, the Asteroid Belt has long been a source of fascination for astronomers. Initially, they wondered why the many objects that make it up did not come together to form a planet. But more recently, human beings have been eyeing the Asteroid Belt for other purposes.
Whereas most of our efforts are focused on research – in the hopes of shedding additional light on the history of the Solar System – others are looking to tap for its considerable wealth. With enough resources to last us indefinitely, there are many who want to begin mining it as soon as possible. Because of this, knowing exactly how long it would take for spaceships to get there and back is becoming a priority.
Distance from Earth:
The distance between the Asteroid Belt and Earth varies considerably depending on where we measure to. Based on its average distance from the Sun, the distance between Earth and the edge of the Belt that is closest to it can be said to be between 1.2 to 2.2 AUs, or 179.5 and 329 million km (111.5 and 204.43 million mi).
However, at any given time, part of the Asteroid Belt will be on the opposite side of the Sun, relative to Earth. From this vantage point, the distance between Earth and the Asteroid Blt ranges from 3.2 and 4.2 AU – 478.7 to 628.3 million km (297.45 to 390.4 million mi). To put that in perspective, the distance between Earth and the Asteroid Belt ranges between being slightly more than the distance between the Earth and the Sun (1 AU), to being the same as the distance between Earth and Jupiter (4.2 AU) when they are at their closest.
But of course, for reasons of fuel economy and time, asteroid miners and exploration missions are not about to take the long way! As such, we can safely assume that the distance between Earth and the Asteroid Belt when they are at their closest is the only measurement worth considering.
Past Missions:
The Asteroid Belt is so thinly populated that several unmanned spacecraft have been able to move through it on their way to the outer Solar System. In more recent years, missions to study larger Asteroid Belt objects have also used this to their advantage, navigating between the smaller objects to rendezvous with bodies like Ceres and Vesta. In fact, due to the low density of materials within the Belt, the odds of a probe running into an asteroid are now estimated at less than one in a billion.
The first spacecraft to make a journey through the asteroid belt was the Pioneer 10 spacecraft, which entered the region on July 16th, 1972 (a journey of 135 days). As part of its mission to Jupiter, the craft successfully navigated through the Belt and conducted a flyby of Jupiter (in December of 1973) before becoming the first spacecraft to achieve escape velocity from the Solar System.
For the most part, these missions were part of missions to the outer Solar System, where opportunities to photograph and study asteroids were brief. Only the Dawn, NEAR and JAXA’s Hayabusamissions have studied asteroids for a protracted period in orbit and at the surface. Dawn explored Vesta from July 2011 to September 2012, and is currently orbiting Ceres (and sending back gravity data on the dwarf planet’s gravity) and is expected to remain there until 2017.
Fastest Mission to Date:
The fastest mission humanity has ever mounted was the New Horizons mission, which was launched from Earth on Jan. 19th, 2006. The mission began with a speedy launch aboard an Atlas V rocket, which accelerated it to a a speed of about 16.26 km per second (58,536 km/h; 36,373 mph). At this speed, the probe reached the Asteroid Belt by the following summer, and made a close approach to the tiny asteroid 132524 APL by June 13th, 2006 (145 days after launching).
However, even this pales in comparison to Voyager 1, which was launched on Sept. 5th, 1977 and reached the Asteroid Belt on Dec. 10th, 1977 – a total of 96 days. And then there was the Voyager 2 probe, which launched 15 days after Voyager 1 (on Sept. 20th), but still managed to arrive on the same date – which works out to a total travel time of 81 days.
Not bad as travel times go. At these speed, a spacecraft could make the trip to the Asteroid Belt, spend several weeks conducting research (or extracting ore), and then make it home in just over six months time. However, one has to take into account that in all these cases, the mission teams did not decelerate the probes to make a rendezvous with any asteroids.
Ergo, a mission to the Asteroid Belt would take longer as the craft would have to slow down to achieve orbital velocity. And they would also need some powerful engines of their own in order to make the trip home. This would drastically alter the size and weight of the spacecraft, which would inevitably mean it would be bigger, slower and a heck of a lot more expensive than anything we’ve sent so far.
Another possibility would be to use ionic propulsion (which is much more fuel efficient) and pick up a gravity assist by conducting a flyby of Mars – which is precisely what the Dawn mission did. However, even with a boost from Mars’ gravity, the Dawn mission still took over three years to reach the asteroid Vesta – launching on Sept. 27th, 2007, and arriving on July 16th, 2011, (a total of 3 years, 9 months, and 19 days). Not exactly good turnaround!
Proposed Future Methods:
A number of possibilities exist that could drastically reduce both travel time and fuel consumption to the Asteroid Belt, many of which are currently being considered for a number of different mission proposals. One possibility is to use spacecraft equipped with nuclear engines, a concept which NASA has been exploring for decades.
In a Nuclear Thermal Propulsion (NTP) rocket, uranium or deuterium reactions are used to heat liquid hydrogen inside a reactor, turning it into ionized hydrogen gas (plasma), which is then channeled through a rocket nozzle to generate thrust. A Nuclear Electric Propulsion (NEP) rocket involves the same basic reactor converting its heat and energy into electrical energy, which would then power an electrical engine.
In both cases, the rocket would rely on nuclear fission or fusion to generates propulsion rather than chemical propellants, which has been the mainstay of NASA and all other space agencies to date. According to NASA estimates, the most sophisticated NTP concept would have a maximum specific impulse of 5000 seconds (50 kN·s/kg).
Using this engine, NASA scientists estimate that it would take a spaceship only 90 days to get to Mars when the planet was at “opposition” – i.e. as close as 55,000,000 km from Earth. Adjusted for a distance of 1.2 AUs, that means that a ship equipped with a NTP/NEC propulsion system could make the trip in about 293 days (about nine months and three weeks). A little slow, but not bad considering the technology exists.
Another proposed method of interstellar travel comes in the form of the Radio Frequency (RF) Resonant Cavity Thruster, also known as the EM Drive. Originally proposed in 2001 by Roger K. Shawyer, a UK scientist who started Satellite Propulsion Research Ltd (SPR) to bring it to fruition, this drive is built around the idea that electromagnetic microwave cavities can allow for the direct conversion of electrical energy to thrust.
According to calculations based on the NASA prototype (which yielded a power estimate of 0.4 N/kilowatt), a spacecraft equipped with the EM drive could make the trip to Mars in just ten days. Adjusted for a trip to the Asteroid Belt, so a spacecraft equipped with an EM drive would take an estimated 32.5 days to reach the Asteroid Belt.
Impressive, yes? But of course, that is based on a concept that has yet to be proven. So let’s turn to yet another radical proposal, which is to use ships equipped with an antimatter engine. Created in particle accelerators, antimatter is the most dense fuel you could possibly use. When atoms of matter meet atoms of antimatter, they annihilate each other, releasing an incredible amount of energy in the process.
According to the NASA Institute for Advanced Concepts (NIAC), which is researching the technology, it would take just 10 milligrams of antimatter to propel a human mission to Mars in 45 days. Based on this estimate, a craft equipped with an antimatter engine and roughly twice as much fuel could make the trip to the Asteroid Belt in roughly 147 days. But of course, the sheer cost of creating antimatter – combined with the fact that an engine based on these principles is still theoretical at this point – makes it a distant prospect.
Basically, getting to the Asteroid Belt takes quite a bit of time, at least when it comes to the concepts we currently have available. Using theoretical propulsion concepts, we are able to cut down on the travel time, but it will take some time (and lots of money) before those concepts are a reality. However, compared to many other proposed missions – such as to Europa and Enceladus – the travel time is shorter, and the dividends quite clear.
As already stated, there are enough resources – in the form of minerals and volatiles – in the Asteroid Belt to last us indefinitely. And, should we someday find a way to cost-effective way to send spacecraft there rapidly, we could tap that wealth and begin to usher in an age of post-scarcity! But as with so many other proposals and mission concepts, it looks like we’ll have to wait for the time being.
In the 18th century, observations made of all the known planets (Mercury, Venus, Earth, Mars, Jupiter and Saturn) led astronomers to the realization that there was a pattern in their orbits. Eventually, this led to the Titius–Bode law, which predicted the amount of space that naturally existed between each celestial body that orbited our Sun. In accordance with this law, astronomers noted that there appeared to be a discernible gap between the orbits of Mars and Jupiter.
Investigations into this gap eventually resulted in astronomers observing several bodies of various size. This led to the creation of the term “asteroid” (Greek for ‘star-like’ or ‘star-shaped’), as well as “Asteroid Belt”, once it became clear just how many there were. Through various methods, astronomers have since confirmed the existence of several million objects between the orbit of Mars and Jupiter. They have also determined, with a certain degree of accuracy, how far it is from our planet.
Structure and Composition:
The Asteroid Belt consists of several large bodies, coupled with millions of smaller size. The larger bodies, such as Ceres, Vesta, Pallas, and Hygiea, account for half of the belt’s total mass, with almost one-third accounted for by Ceres alone. Beyond that, over 200 asteroids that are larger than 100 km in diameter, and 0.7–1.7 million asteroids with a diameter of 1 km or more.
It total, the Asteroid Belt’s mass is estimated to be 2.8×1021 to 3.2×1021 kilograms – which is equivalent to about 4% of the Moon’s mass. While most asteroids are composed of rock, a small portion of them contain metals such as iron and nickel. The remaining asteroids are made up of a mix of these, along with carbon-rich materials. Some of the more distant asteroids tend to contain more ices and volatiles, which includes water ice.
Despite the impressive number of objects contained within the belt, the Main Belt’s asteroids are also spread over a very large volume of space. As a result, the average distance between objects is roughly 965,600 km (600,000 miles), meaning that the Main Belt consists largely of empty space. In fact, due to the low density of materials within the Belt, the odds of a probe running into an asteroid are now estimated at less than one in a billion.
The main (or core) population of the asteroid belt is sometimes divided into three zones, which are based on what is known as “Kirkwood gaps”. Named after Daniel Kirkwood, who announced in 1866 the discovery of gaps in the distance of asteroids, these gaps are similar to what is seen with Saturn’s and other gas giants’ systems of rings.
Orbit Around the Sun:
Located between Mars and Jupiter, the belt ranges in distance between 2.2 and 3.2 astronomical units (AU) from the Sun – 329 million to 478.7 million km (204.43 million to 297.45 million mi). It is also an estimated 1 AU thick (149.6 million km, or 93 million mi), meaning that it occupies the same amount of distance as what lies between the Earth to the Sun.
The distance of an asteroid from the Sun (its semi-major axis) depends upon its distribution into one of three different zones based on the Belt’s “Kirkwood Gaps”. Zone I lies between the 4:1 resonance and 3:1 resonance Kirkwood gaps, which are roughly 2.06 and 2.5 AUs (3 to 3.74 billion km; 1.86 to 2.3 billion mi) from the Sun, respectively.
Zone II continues from the end of Zone I out to the 5:2 resonance gap, which is 2.82 AU (4.22 billion km; 2.6 mi) from the Sun. Zone III, the outermost section of the Belt, extends from the outer edge of Zone II to the 2:1 resonance gap, located some 3.28 AU (4.9 billion km; 3 billion mi) from the Sun.
Distance from Earth:
The distance between the Asteroid Belt and Earth varies considerably depending on where we measure to. Based on its average distance from the Sun, the distance between Earth and the closest edge of the Belt can be said to be between 1.2 to 2.2 AUs, or 179.5 and 329 million km (111.5 and 204.43 million mi). But of course, at any given time, part of the Asteroid Belt will be on the opposite side of the Sun relative to us as well.
From this vantage point, the distance between Earth and the Asteroid Belt ranges from 3.2 and 4.2 AU – 478.7 to 628.3 million km (297.45 to 390.4 million mi). To put that in perspective, the distance between Earth and the Asteroid Belt ranges from being slightly more than the distance between the Earth and the Sun (1 AU), to being the same as the distance between Earth and Jupiter (4.2 AU) when they are at their closest.
Naturally, any exploration or other kind of mission launched from Earth is going to take the shortest route, unless it is aiming for a specific asteroid. And even then, mission planners will time the launch to ensure that we are closest to the destination. Hence, we can safely use the estimates of 1.2 – 2.2 AU to gauge the distance between us and the Main Belt.
Even so, at its closest, getting to the Asteroid Belt would involve a bit of a hike! In short, it is approximately 179.5 million km (or 111.5 million mi) distant from us at any given time. As such, knowing just how much time and energy it would take to get their and back is going to come in handy if and when we begin mounting crewed missions to the Belt, not to mention the prospect of asteroid mining!