Close
Date TimeJuly 01, 2018
VoiceWhen astronomers first spied a weird cigar-shaped object speeding past the sun last October, they could tell from its path that it had come from another star system — but they didn't know exactly what it was.
Mysterious Oumuamua space object has finally been identified
Now they know. A study published Wednesday in the journal Nature indicates that the interstellar visitor, dubbed Oumuamua, is neither an asteroid nor an alien spacecraft (as some wags had suggested) but a small interstellar comet.
"It's the only such object discovered so far," Marco Micheli, an astronomer with the European Space Agency and the lead author of the new study, told NBC News MACH in an email.
Mysterious Oumuamua space object has finally been identified
Comets — icy, dusty objects that have been likened to "dirty snowballs" — typically form long tails when they come close to the sun. No such tail was visible in earlier observations of Oumuamua (which means "scout" in Hawaiian), a fact that helped lead other astronomers to conclude that it was an asteroid.
But an analysis of new observations made by ground-based telescopes and the Hubble Space Telescope yielded a surprise: Oumuamua's trajectory couldn't be explained solely by the gravitational forces exerted on it by the sun and the planets — as would be the case if it were an asteroid, or space rock.
"Unexpectedly, we found that Oumuamua was not slowing down as fast as it should have under gravitational forces alone," Micheli said in a statement.
His team concluded that the unexpected motion of Oumuamua had to be caused by the spewing out of small quantities of gaseous materials from its surface. This "outgassing" — commonly seen in comets — was too small to be visible but significant enough to affect Oumuamua's trajectory.
But not everyone is buying that explanation — at least not completely.
Alan Jackson, an astronomer at the University of Toronto Scarborough, told MACH in an email that if Oumuamua is a comet, it must be one that lost much of its ice before leaving its home star system.
"A comet that has lost enough of its ice is essentially the same as an asteroid," he said. "Oumuamua thus seems to be in that ambiguous region between the two."
Jackson conducted previous research on Oumuamua but was not involved in the new study.
Whatever its precise identity, Oumuamua might be just the first of many such interstellar visitors we'll encounter. Jackson said new telescopes should help astronomers find "a lot more objects like Oumuamua and we will then be able to put together a more complete picture of what the building blocks of planets look like in other planetary systems, which will also help us to understand how planets form."
Oumaumau is now headed to the outer solar system at a speed of about 70,000 miles per hour. Astronomers expect it to pass Neptune's orbit in four years.
"The object is now too faint to observe, so no new data will be acquired," Micheli said in the email. "But I expect scientists will keep working on their data for quite some time."

Related Stories
Is The Spider On Face Snapchat Filter Harmless Or Traumatic? We Asked A PsychologistIs The Spider On Face Snapchat Filter Harmless Or Traumatic? We Asked A Psychologist
Stephen Colbert, Trevor Noah, and Jimmy Kimmel hit Trumps about-to-lose-power trio of impeachment-kissed aidesStephen Colbert, Trevor Noah, and Jimmy Kimmel hit Trump's 'about-to-lose-power trio' of impeachment-kissed aides
Stephen Colbert chides Trump for stealing his Colbert Report alligator-moat bit from ObamaStephen Colbert chides Trump for stealing his Colbert Report alligator-moat bit from Obama
Stormzy Calls For Piece Of S*** Jacob Rees-Mogg To Resign Over Grenfell CommentsStormzy Calls For 'Piece Of S***' Jacob Rees-Mogg To Resign Over Grenfell Comments
Is It Ever Okay To Scare Your Child? We Asked A PsychologistIs It Ever Okay To Scare Your Child? We Asked A Psychologist
Migrant Alleged to Have Raped Woman Immediately after Sheriff’s Office Ignored ICE Detainer and Released Him Is ArrestedMigrant Alleged to Have Raped Woman Immediately after Sheriff’s Office Ignored ICE Detainer and Released Him Is Arrested
Nasa All-Female Spacewalk Will See Astronauts Christina Koch And Jessica Meir Make HistoryNasa All-Female Spacewalk Will See Astronauts Christina Koch And Jessica Meir Make History
SpaceX launches another 60 Starlink satellites while setting two rocket reuse recordsSpaceX launches another 60 Starlink satellites while setting two rocket reuse records
Gemma Collins Reckons She Has Superpowers Like Eleven From Stranger ThingsGemma Collins Reckons She Has Superpowers Like Eleven From Stranger Things
NASA conducts spacewalk as worlds 1st spacewalker diesNASA conducts spacewalk as world's 1st spacewalker dies
Latest News
The Latest: Beshear urges unity after his rival’s concessionThe Latest: Beshear urges unity after his rival’s concession
Transcript Shows WH Made Up Details of Trump’s Zelensky CallTranscript Shows WH Made Up Details of Trump’s Zelensky Call
French police ratchet up evidence search in Epstein probeFrench police ratchet up evidence search in Epstein probe
Come back tomorrow: battling for asylum in South Africa'Come back tomorrow': battling for asylum in South Africa
He essentially added an article of impeachment in real-time: Trump criticised by Fox News and Ken Starr for attacking Yovanovitch during hearing'He essentially added an article of impeachment in real-time': Trump criticised by Fox News and Ken Starr for attacking Yovanovitch during hearing
Bolivia Expels Maduro’s Diplomats in Abrupt Foreign Policy ShiftBolivia Expels Maduro’s Diplomats in Abrupt Foreign Policy Shift
Euro 2020: Finland seal qualification, Romania v Sweden – live clockwatch!Euro 2020: Finland seal qualification, Romania v Sweden – live clockwatch!
Rafael Nadal overcomes Stefanos Tsitsipas after epic struggleRafael Nadal overcomes Stefanos Tsitsipas after epic struggle
Saracens start Champions Cup defence under storm cloudsSaracens start Champions Cup defence under storm clouds
NFL hits Browns Myles Garrett with indefinite ban for helmet attackNFL hits Browns' Myles Garrett with indefinite ban for helmet attack
Leaders
Donald-TrumpDonald Trump
45th President of the United States of America
Mike-PenceMike Pence
Vice President of the United States
Boris-JohnsonBoris Johnson
British Prime Minister
Angela-MerkelAngela Merkel
Chancellor of Germany
Emmanuel-MacronEmmanuel Macron
President of France
Justin-TrudeauJustin Trudeau
Prime Minister of Canada
Nancy-PelosiNancy Pelosi
Speaker of the United States House of Representatives
Barack-ObamaBarack Obama
44th U.S. President
Theresa-MayTheresa May
Member of Parliament of the United Kingdom
Vladimir-PutinVladimir Putin
Russian President
Shinzo-AbeShinzō Abe
Prime Minister of Japan
Related Stories
Is The Spider On Face Snapchat Filter Harmless Or Traumatic? We Asked A PsychologistIs The Spider On Face Snapchat Filter Harmless Or Traumatic? We Asked A Psychologist
Stephen Colbert, Trevor Noah, and Jimmy Kimmel hit Trumps about-to-lose-power trio of impeachment-kissed aidesStephen Colbert, Trevor Noah, and Jimmy Kimmel hit Trump's 'about-to-lose-power trio' of impeachment-kissed aides
Stephen Colbert chides Trump for stealing his Colbert Report alligator-moat bit from ObamaStephen Colbert chides Trump for stealing his Colbert Report alligator-moat bit from Obama
Stormzy Calls For Piece Of S*** Jacob Rees-Mogg To Resign Over Grenfell CommentsStormzy Calls For 'Piece Of S***' Jacob Rees-Mogg To Resign Over Grenfell Comments
Is It Ever Okay To Scare Your Child? We Asked A PsychologistIs It Ever Okay To Scare Your Child? We Asked A Psychologist
Migrant Alleged to Have Raped Woman Immediately after Sheriff’s Office Ignored ICE Detainer and Released Him Is ArrestedMigrant Alleged to Have Raped Woman Immediately after Sheriff’s Office Ignored ICE Detainer and Released Him Is Arrested
Nasa All-Female Spacewalk Will See Astronauts Christina Koch And Jessica Meir Make HistoryNasa All-Female Spacewalk Will See Astronauts Christina Koch And Jessica Meir Make History
SpaceX launches another 60 Starlink satellites while setting two rocket reuse recordsSpaceX launches another 60 Starlink satellites while setting two rocket reuse records
Gemma Collins Reckons She Has Superpowers Like Eleven From Stranger ThingsGemma Collins Reckons She Has Superpowers Like Eleven From Stranger Things
NASA conducts spacewalk as worlds 1st spacewalker diesNASA conducts spacewalk as world's 1st spacewalker dies
Latest News
The Latest: Beshear urges unity after his rival’s concessionThe Latest: Beshear urges unity after his rival’s concession
Transcript Shows WH Made Up Details of Trump’s Zelensky CallTranscript Shows WH Made Up Details of Trump’s Zelensky Call
French police ratchet up evidence search in Epstein probeFrench police ratchet up evidence search in Epstein probe
Come back tomorrow: battling for asylum in South Africa'Come back tomorrow': battling for asylum in South Africa
He essentially added an article of impeachment in real-time: Trump criticised by Fox News and Ken Starr for attacking Yovanovitch during hearing'He essentially added an article of impeachment in real-time': Trump criticised by Fox News and Ken Starr for attacking Yovanovitch during hearing
Bolivia Expels Maduro’s Diplomats in Abrupt Foreign Policy ShiftBolivia Expels Maduro’s Diplomats in Abrupt Foreign Policy Shift
Euro 2020: Finland seal qualification, Romania v Sweden – live clockwatch!Euro 2020: Finland seal qualification, Romania v Sweden – live clockwatch!
Rafael Nadal overcomes Stefanos Tsitsipas after epic struggleRafael Nadal overcomes Stefanos Tsitsipas after epic struggle
Saracens start Champions Cup defence under storm cloudsSaracens start Champions Cup defence under storm clouds
NFL hits Browns Myles Garrett with indefinite ban for helmet attackNFL hits Browns' Myles Garrett with indefinite ban for helmet attack
Leaders
Donald-TrumpDonald Trump
45th President of the United States of America
Mike-PenceMike Pence
Vice President of the United States
Boris-JohnsonBoris Johnson
British Prime Minister
Angela-MerkelAngela Merkel
Chancellor of Germany
Emmanuel-MacronEmmanuel Macron
President of France
Justin-TrudeauJustin Trudeau
Prime Minister of Canada
Nancy-PelosiNancy Pelosi
Speaker of the United States House of Representatives
Barack-ObamaBarack Obama
44th U.S. President
Theresa-MayTheresa May
Member of Parliament of the United Kingdom
Vladimir-PutinVladimir Putin
Russian President
Shinzo-AbeShinzō Abe
Prime Minister of Japan
French convict escapes prison again -- this time with a hijacked helicopter
Russia knocks out Spain in penalty shootout
Operation UFO: Britain's race to beat Russia to alien weapons REVEALED in secret files
Rocket bursts into flames in Japan after second failed launch
Meet the 4 candidates vying to become Mexico's president
Trump Pressures Saudi Arabia to Increase Oil Production
9 injured in mass stabbing at Idaho apartment complex
Iran protest turns violent; at least 1 death reported
French protest Macron's new reduced speed limits
US ambassador to Estonia resigns over Trump policies and provocations
Ex-NASA scientist says aliens exist but encounters are covered up by governments
Cristiano Ronaldo's World Cup ends as Uruguay beats Portugal
Reporter resigns after false tweet that Maryland shooting suspect had MAGA hat
North Korea has increased nuclear production at secret sites, say US officials
7 days in the dark: How the Thailand cave search unfolded
Comcast is experiencing a nationwide outage
Serena Williams and baby Alexis inspect Wimbledon's childcare arrangement before going back to work
See the 'Space Jellyfish' and Other Jaw-Dropping Views from SpaceX's Dragon Launch
Alexandria Ocasio-Cortez Breaks Down Viral Reaction to Democratic Primary Win
Trump Responds To Annapolis Shooting
Susan Sarandon Arrested Protesting Trump’s Immigration Policy
Michael Moore Reveals Release Date for His Anti-Trump Doc
FREXIT? Donald Trump 'told Macron to pull France out of EU in return for US trade deal'
Pence tells Central American leaders that illegal immigration to U.S. ‘must end’
NASA uses Earth as laboratory to study distant worlds
Rob. Gerald. John. Rebecca. Wendi. These are the victims of the newsroom shooting
The Biggest Bombshells Drake Drops on His New Album
SpaceX is sending an AI robot 'crew member' to join the astronauts on the space station
Why Ellen DeGeneres Divorce Rumors Made Portia de Rossi Feel ‘Accepted’
Forget the football, Vladimir Putin is the real World Cup winner
Maryland shooting: Gunman 'OPENS FIRE' at Capital Gazette newsroom - 'MULTIPLE FATALITIES'
You can finally follow Julia Roberts on Instagram
Melania Trump arrives in Arizona for her second trip to immigration facilities
Summit between Donald Trump and Vladimir Putin to be held in Helsinki on July 16
England team news: Jamie Vardy set to start against Belgium in Harry Kane selection clue
'You have not been forgotten,' Prince William tells Palestinians
Late-Night Weighs In On Justice Anthony Kennedy's Supreme Court Shakeup
Milky Way is full of 'space grease,' study finds
Trump and Putin to reveal details of first official summit
President Trump says process to replace Kennedy on Supreme Court will 'begin immediately'
Launch of NASA's James Webb Space Telescope delayed again as costs rise
What the hell was that, Germany?
Laura Benanti Brings Back Melania Trump Impression to Discuss 'I Really Don't Care' Jacket
Joe Jackson, musical family patriarch, dead at 89
Who is Alexandria Ocasio-Cortez?
David Beckham joins Duke and Duchess of Sussex and Queen at young leaders awards ceremony
Huge EXPLOSION at Texas Hospital - 'building collapse' leaves one dead and a dozen injured
Japan space explorer arrives at asteroid to collect samples
Late-Night Hosts Sound Off on SCOTUS Upholding Trump Travel Ban
Trump plots controversial Putin meeting and leaves NATO allies guessing
Argentina avoids humiliation with late winner against Nigeria
This Scientist Thinks Aliens Will Need to 'Catch' Stars to Survive
Uber wins right to keep operating in London
Trump scores huge win over controversial travel ban
Two dead and 18 injured after Cambridgeshire bus-lorry crash
Emmanuel Macron holds long meeting with Pope Francis
Cardi B confirms she secretly married Offset in September, before they were 'engaged'
Houston Rockets star James Harden wins 2017-2018 NBA MVP
Police dog 'performs CPR' in adorable viral video
Jimmy Fallon responds to Trump: 'Why are you tweeting at me?'
Democrat's ad for run in Texas goes viral
Richard Harrison, Known as 'The Old Man' on 'Pawn Stars,' Dies at 77
Iran so close to stunning Portugal but Quaresma goal enough for draw
Protesters swarm Iran's Grand Bazaar in Tehran, force shops to close in anger over economy
NASA's stunning new photo of Jupiter looks like a work of art
AI bots from a lab backed by Elon Musk trained for thousands of lifetimes to beat humans at Dota 2
What Erdogan's reelection means for Turkey and the world
Stunning NASA photo shows blue sand dune on Mars, the Red Planet
Trump Responds To Restaurant Kicking Out Sanders, Calls It ‘Dirty’
BET Awards: Meek Mill Pays Tribute to XXXTentacion While Performing 'Stay Woke'
Prince William reveals childhood details about Kate during historical Middle East tour
Thousands flee as flames race across dry rural California
Black Astronaut Jeanette Epps Still Doesn't Know Why NASA Cancelled Her Historic Mission This Year
Trump Attacks Jimmy Fallon for Hollywood Reporter Podcast 'Hair Tussle' Comments: 'Be a Man, Jimmy!'
Erodgan declares victory in Turkey presidential election
Donald Hall, US poet laureate and prize-winning man of letters, dies at 89
Donald Trump vows to deport illegal immigrants IMMEDIATELY without trial
Why Lionel Messi hates playing for Argentina in World Cup
Prince William starts historic Middle East tour
Mo Salah considering quitting Egypt national team
Turkey elections: Erdogan ahead in early results
GERMANY EXPLOSION: At least 25 injured in blast sparking multiple fires
World's Ugliest Dog title goes to English bulldog named Zsa Zsa
Tom Holland Reveals Next 'Spider-Man' Movie Is Called 'Far From Home'
New Zealand prime minister Jacinda Ardern introduces baby Neve te Aroha to the world
Trump-Putin meeting will follow Bolton trip to Moscow, says Pompeo
Saudi women in the driver’s seat — and in the crosshairs of change
Turkey elections: Polls open in tough challenge for Erdogan
Toni Kroos brings off late miracle for Germany to stun Sweden
Eddie Vedder's wife, more stars are responding to Melania Trump with their own jackets
8 perfect astronaut selfies for when you just need some space
Sarah Huckabee Sanders Got Kicked Out Of A Restaurant Because Of Trump
'Game of Thrones' stars Kit Harington and Rose Leslie are married
OPEC meets Russia, other allies to agree oil output boost
Romelu Lukaku and Eden Hazard star as Belgium rout Tunisia
Tom Arnold Went On TV To Hype Up Getting Dirt On Trump And Boy Did Things Get Awkward
Hundreds of women march in Rio to demand legal abortion
Jimmy Fallon Launches First-Ever 'Tonight Show' Book Club
Vinnie Paul, Pantera drummer and co-founder, dies at 54
Four people arrested in Pittsburgh protests over death of Antwon Rose
'Modern Family' star Sarah Hyland shares shocking photo of swollen face after hospitalization
Face-scanning technology at Orlando airport expands to all international travelers
Sleeping beauty discovered 2,000 years after death wearing skirt and clutching make up box
Summer camp illness in Florida sends 33 kids, 3 adults to hospital
Biggest winners and losers of 2018 NBA draft
World Cup: Fan Apologizes to TV Reporter For Groping Her on Live TV
Lewandowski Still Refuses to Apologize For ‘Womp Womp’ Comment
Airbus plans UK job cuts amid fears of hard Brexit impact
Utah Jazz select Grayson Allen with 21st pick
Charing Cross station in London evacuated after bomb threat
SpaceX's massive Falcon Heavy rocket lands $130 million military launch contract
Kim Kardashian Tries To Defend Wearing Fulani Braids Again
Colbert Mocks Melania’s Jacket: Was ‘Womp Womp’ Your First Choice?
WaPo: National Enquirer sent Trump stories to Michael Cohen before publication
Shock moment parents snatch baby from priest after he SLAPS crying child
Donald Trump And Immigrant Girl Meet Face To Face On TIME Cover
Melania Trump To Child Detainees: ‘Good Luck’
Argentina on the brink of early World Cup elimination after defeat by Croatia
Sophie Gradon, former Love Island contestant, dies aged 32
Koko the Gorilla, Famous for Learning Sign Language, Has Died
Stonehenge built using Pythagoras’ theorem 2,000 years BEFORE philosopher's birth
Peter Fonda apologizes for ‘highly inappropriate’ Barron Trump tweet
St. Petersburg's white nights light up fans' World Cup
Trump and Putin plan to meet in mid-July
Wife of Israeli Prime Minister charged with fraud
Crowd gathers at LaGuardia Airport to support children believed to be separated from families
Instagram unveils new video service IGTV in challenge to YouTube
Burger King apologises for Russian ad offering burgers for getting pregnant to World Cup players
Michael Moore to Honor Jane Fonda With Lifetime Achievement Award
Jacinda Ardern: New Zealand Prime Minister gives birth to a baby girl
Diego Costa gets luck of the bounce as Spain deny unfortunate Iran
In rare reversal, Trump signs order ending family separations, but ‘zero-tolerance’ immigration policy stays
Tesla Sues Ex-Employee Alleging Data Theft, Leaks to Media
Obama Breaks Silence On Family Separations
Cristiano Ronaldo makes more history as Portugal beat Morocco
World Cup reporter sexually assaulted on live TV
Amid the World Cup, Vladimir Putin scores some diplomatic goals
Ann Coulter Is Reamed On Twitter For Calling Immigrant Kids ‘Child Actors’
Yemeni prisoners say Emirati officers sexually torture them
Trevor Noah: Even Trump Is Against Trump Separating Kids From Their Parents
Stephen Colbert Rebukes Sarah Huckabee Sanders Amid Family Separations
MSNBC Host Struggles To Read Report Of Babies Sent To ‘Tender Age’ Shelters
Australian telecom giant Telstra is slashing 8,000 jobs
Canada becomes second nation in the world to legalize marijuana
US withdrawing from UN Human Rights Council
Artem Dzyuba secures second win for Russia with victory over Egypt
Southgate tube station LOCKDOWN: Several injured in 'explosion' - Police surround scene
U.S. expected to back away from UN Human Rights Council
Supposed 'alien ship' crashed on Mars has a much more mundane explanation
James Corden Stages Andrew Lloyd Webber-Themed 'Crosswalk the Musical' in London
Barack Obama Gets School Named After Him In Former Confederate Capital
Turkey to get F-35 jets Thursday despite opposition from Congress
What is Juneteenth? Day marks the end of slavery in the United States
Turkey CRISIS: Arrest of 124 coup supporters ordered as Erdogan faces LOSING power
Laura Ingraham Compares Child Immigrant Detention Centers To Summer Camps
Rapper Jimmy Wopo Shot Dead in Pittsburgh Drive-By
'Call me Mr President’: Emmanuel Macron scolds teenager
Kim Jong Un to visit China this week
Android Messages will let you send texts from your computer starting today
MTV Movie & TV Awards: Host Tiffany Haddish's Opening Monologue
Colbert Plays Devil’s Advocate On The Issue Of Separating Immigrant Families
Emilia Clarke Says Goodbye To ‘Game Of Thrones’ In An Emotional Post
Angelina Jolie: We Must Not Forget The People Of Mosul
ZTE stock drops more than 20% after US Senate pushes to keep ban
Rapper XXXTentacion, 20, shot dead
Harry Kane double ensures England defeat Tunisia in World Cup opener
Eurozone reform ‘within reach’ France warns as Merkel backs Macron plan
Malmo shooting: Swedish police warn several injured in city centre attack
Kate Spade’s funeral to be held in birthplace of Kansas City
Israel arrests former government minister for Iran spying
Trump's 'Space Force' Motivated By Russian, Chinese Threats To Critical US Orbital Systems
Richard Valeriani, Longtime 'NBC Nightly News' Correspondent, Dies at 85
Sandra Bullock Says She Was Afraid Of Working With Harvey Weinstein
Ivanka's deafening silence
French air traffic control 'causes third of Europe's flight delays'
Trump says Germans ‘turning against their leadership’ over immigration
Michael Jackson's old pet elephant, Ali, escapes enclosure at Florida zoo
Astronaut Chris Hadfield says the rockets from NASA, SpaceX, and Blue Origin won't take people to Mars
Audi CEO Arrested In Germany Over Diesel Scandal
Meghan Markle's dad reveals warning to Harry as he breaks silence in tell-all interview
White House adviser Kellyanne Conway says ‘nobody likes’ family separation policy
Egypt goalkeeper declines beer-sponsored World Cup award
Elon Musk shows off new Tesla production line — and it's in a tent
Google to invest $550 million in Chinese e-commerce giant JD.com
Gunman wounds 2, is fatally shot by bystander at Walmart store
Japan quake kills 3
Ex-Trump operative met with Russian 'offering Clinton dirt for $2M'
Switzerland’s Zuber heads controversial equaliser to deny Brazil victory
Everything you need to know about the final round of the US Open
Mexico stun defending champs Germany
Why Germany will beat Mexico
New Jersey arts festival shooting leaves 20 injured, 1 suspect dead, officials say
Mars will come closer to Earth in the coming weeks than it has been in 15 years — here's how to see it
Greece and Macedonia sign deal on name change
Tesla goes up in flames in video captured by actor Mary McCormack
Two Kansas deputies shot and killed by inmate while escorting him to court, authorities say
Beyoncé and Jay-Z drop joint album
17 dead after Venezuela nightclub violence
Pope: Abortion is ‘white glove’ equivalent to Nazi crimes
Messi misses penalty, Iceland holds Argentina to 1-1 draw
Close