#Organic chemistry in space
Amino acids, sugars and nucleobases: the building blocks of life found in meteorites and asteroid samples.
Some meteorites, especially carbonaceous chondrites, contain a surprising variety of carbon compounds that formed without any help from life. The Murchison meteorite, which fell in Australia in 1969, holds dozens of different amino acids, the building blocks of proteins.
Sugars, including ribose, part of the RNA molecule, and all five of the nucleobases used in DNA and RNA have since been identified in meteorites.
Samples brought back from the asteroids Ryugu and Bennu, untouched by Earth, confirm that molecules like these form in space. That raises a fascinating question: how much of the raw material for life was delivered to the young Earth by falling meteorites?
Part of Meteorites across the sciences.
Lessons (1)
- Carbonaceous chondritesCarbonaceous chondrites are rare, often dark and crumbly, and scientifically priceless.
Courses (5)
- Chirality and the origin of lifeLife uses left-handed amino acids almost exclusively. Some meteorites contain a small excess of left-handed forms, a clue to how this prefer
- Water and the ingredients of lifeSome meteorites carry water locked in minerals and a rich chemistry of carbon compounds, including amino acids and nucleobases.
- Adult course: Meteorites from first principlesTwelve lessons for adult learners: where meteorites come from, how falls are tracked and recovered, how they are classified and dated, what
- The molecules of life from spaceSome meteorites contain amino acids, the building blocks of proteins, made without any living thing.
- GCSE: Meteorites across the sciencesTwelve lessons that use meteorites to practise GCSE physics, chemistry and biology: the formation of the Solar System, isotopes and half-lif
Famous meteorites (6)
- ALH 84001A potato-sized rock from Mars that sparked a worldwide debate about life beyond Earth.
- MurchisonA stone that fell on an Australian town in 1969, packed with the chemical building blocks of life.
- OrgueilA crumbly black meteorite from 1864 whose chemistry is the closest match on Earth to the Sun itself.
- Sutter's MillIn 2012 a rare carbon-rich meteorite fell on the very spot where the California Gold Rush began – and weather radar helped find it.
- Tagish LakeA fragile carbon-rich meteorite that fell onto a frozen Canadian lake in 2000 and was collected without being touched by bare hands.
- WinchcombeThe 2021 fireball filmed across Britain that delivered the UK's first carbonaceous chondrite – onto a family's driveway.
Meteorite types (4)
- Carbonaceous chondritesRare, often dark chondrites rich in carbon, water-bearing minerals and organic compounds, including the building blocks of life.
- CI chondritesThe chemically most primitive rocks known: their make-up matches the Sun's. CI chondrites, named after Ivuna in Tanzania, match the comp
- CM chondritesWater-rich carbonaceous chondrites full of organic molecules, Murchison and Winchcombe among them.
- CR chondritesMetal-bearing carbonaceous chondrites with some of the most pristine organic matter known.
Space missions (2)
- OSIRIS-RExThe largest asteroid sample ever returned, full of salts, water-formed minerals and life's building blocks.
- Rosetta and PhilaeThe first spacecraft to orbit a comet and to land on one. Rosetta spent ten years catching up with comet 67P/Churyumov–Gerasimenko.
Glossary (7)
Questions and answers (11)
- Do meteorites contain sugars or DNA building blocks?Yes. Some carbonaceous meteorites contain sugars, including ribose, and nucleobases used in DNA and RNA, though not DNA itself.
- Do meteorites contain the building blocks of life?Some do. Carbonaceous chondrites contain amino acids, the components of DNA and RNA called nucleobases, and even sugars, all made by natural
- How can I use meteorites in chemistry lessons?Meteorites show elements and compounds in nature: iron-nickel alloys, silicates, sulfides and even organic molecules, and they link to the o
- How do scientists stop meteorites being contaminated?By collecting fresh falls quickly with clean tools, storing samples in dry nitrogen or vacuum, using clean rooms, and checking isotopes to t
- What are the samples from Ryugu and Bennu?They are pristine samples of two carbon-rich asteroids brought to Earth by spacecraft: about 5.4 grams from Ryugu by Japan's Hayabusa2 i
- What can meteorites tell us about the early Solar System?Meteorites act as a time capsule, recording when the first solids formed, how quickly asteroids and planets grew and melted, which stars con
- What is a carbonaceous chondrite?A carbonaceous chondrite is a primitive stony meteorite rich in carbon compounds and often in water-bearing minerals.
- What is a CM chondrite?A CM chondrite is a carbonaceous chondrite altered by water, rich in clay minerals and organic compounds, such as Murchison and Winchcombe.
- What is the Murchison meteorite?Murchison is a carbonaceous chondrite that fell in Victoria, Australia, on 28 September 1969.
- What was the Tagish Lake meteorite?Tagish Lake is a fragile, carbon-rich meteorite that fell on a frozen lake in Canada on 18 January 2000 and was collected frozen, preserving
- Why was 1969 a special year for meteorites?In 1969 the Allende and Murchison meteorites fell, Japanese scientists found the first concentration of meteorites in Antarctica, and Apollo
Asteroids (1)
- RyuguRyugu is a dark, carbon-rich asteroid about 900 metres across, shaped like a spinning top with a ridge around its equator.
Micrometeorites (2)
- Scoriaceous, unmelted and ultracarbonaceous micrometeoritesNot every micrometeorite melts. Some arrive gently enough to keep the minerals, textures and even the organic matter they had in space, maki
- Water and the ingredients of life: did space dust deliver them?Every year, micrometeorites drop tonnes of carbon and water-bearing minerals onto the Earth.
People (1)
- Dante LaurettaThe University of Arizona scientist who led OSIRIS-REx, the mission that brought about 120 grams of the asteroid Bennu back to Earth in 2023