• Education
    • Higher Education
    • Scholarships & Grants
    • Online Learning
    • School Reforms
    • Research & Innovation
  • Lifestyle
    • Travel
    • Food & Drink
    • Fashion & Beauty
    • Home & Living
    • Relationships & Family
  • Technology & Startups
    • Software & Apps
    • Startup Success Stories
    • Startups & Innovations
    • Tech Regulations
    • Venture Capital
    • Artificial Intelligence
    • Cybersecurity
    • Emerging Technologies
    • Gadgets & Devices
    • Industry Analysis
  • About us
  • Contact
  • Advertise with Us
  • Privacy & Policy
Today Headline
  • Home
  • World News
    • Us & Canada
    • Europe
    • Asia
    • Africa
    • Middle East
  • Politics
    • Elections
    • Political Parties
    • Government Policies
    • International Relations
    • Legislative News
  • Business & Finance
    • Market Trends
    • Stock Market
    • Entrepreneurship
    • Corporate News
    • Economic Policies
  • Science & Environment
    • Space Exploration
    • Climate Change
    • Wildlife & Conservation
    • Environmental Policies
    • Medical Research
  • Health
    • Public Health
    • Mental Health
    • Medical Breakthroughs
    • Fitness & Nutrition
    • Pandemic Updates
  • Sports
    • Football
    • Basketball
    • Tennis
    • Olympics
    • Motorsport
  • Entertainment
    • Movies
    • Music
    • TV & Streaming
    • Celebrity News
    • Awards & Festivals
  • Crime & Justice
    • Court Cases
    • Cybercrime
    • Policing
    • Criminal Investigations
    • Legal Reforms
No Result
View All Result
  • Home
  • World News
    • Us & Canada
    • Europe
    • Asia
    • Africa
    • Middle East
  • Politics
    • Elections
    • Political Parties
    • Government Policies
    • International Relations
    • Legislative News
  • Business & Finance
    • Market Trends
    • Stock Market
    • Entrepreneurship
    • Corporate News
    • Economic Policies
  • Science & Environment
    • Space Exploration
    • Climate Change
    • Wildlife & Conservation
    • Environmental Policies
    • Medical Research
  • Health
    • Public Health
    • Mental Health
    • Medical Breakthroughs
    • Fitness & Nutrition
    • Pandemic Updates
  • Sports
    • Football
    • Basketball
    • Tennis
    • Olympics
    • Motorsport
  • Entertainment
    • Movies
    • Music
    • TV & Streaming
    • Celebrity News
    • Awards & Festivals
  • Crime & Justice
    • Court Cases
    • Cybercrime
    • Policing
    • Criminal Investigations
    • Legal Reforms
No Result
View All Result
Today Headline
No Result
View All Result
Home Science & Environment Space Exploration

Astronomers discover 7 new ‘dark comets,’ but what exactly are they?

December 12, 2024
in Space Exploration
Reading Time: 5 mins read
A A
0
Astronomers discover 7 new 'dark comets,' but what exactly are they?
5
SHARES
11
VIEWS
Share on FacebookShare on Twitter

Scientists have discovered seven more “dark comets,” and analysis of this haul suggests that the puzzling planetoids are divided into two distinct families, further deepening the mystery of why these objects look like asteroids but behave like comets.

Of late, the dividing line between asteroids and comets has become blurred. There are “main-belt comets,” also known as active asteroids, which are comet-like objects possessing the properties of asteroids. Then there are dark comets, which are the opposite: asteroids that have some of the characteristics of comets.

As their name suggests, main-belt comets tend to inhabit the main asteroid belt between Mars and Jupiter. But they grow tails just like a comet, whereas dark comets have no tails but move like a comet, in the sense that they display non-gravitational acceleration. In other words, some other force besides gravity is acting on their motion, changing their trajectory. For a regular comet, this other force is the thrust produced by ices sublimating into vapor on their surface when they near the heat of the sun and outgas into space, carrying the dust that produces their iconic tails. Yet dark comets have no tails.

“When you see that kind of perturbation on a celestial object, it usually means it’s a comet, with volatile material outgassing from its surface giving it a little thrust,” Davide Farnocchia, of NASA’s Jet Propulsion Laboratory in Southern California, said in a statement. “But try as we might, we couldn’t find any signs of a comet’s tail.”

Related: Comets: Everything you need to know about the ‘dirty snowballs’ of space

We’ve seen this mysterious motion before. In 2017, the interstellar object 1I/’Oumuamua sped through the inner solar system before heading back toward interstellar space. As it did so, its trajectory altered from that which gravity alone had planned for it — ‘Oumuamua seemed to be getting an extra push from somewhere.

Although no tails or outgassing were detected coming from ‘Oumuamua, causing its mystery to linger, ‘Oumuamua’s behavior bore a remarkable resemblance to another object found to be acting strangely just a year earlier.

Breaking space news, the latest updates on rocket launches, skywatching events and more!

That object, known as 2003 RM, had been thought to be just another asteroid, until it too was noticed to be moving under a non-gravitational force.

“The fact that the first object we discovered from interstellar space exhibited similar behaviors to 2003 RM made 2003 RM even more intriguing,” said Farnocchia.

By 2023, six other similar objects had been discovered, and the term “dark comet” was used for the first time, in the sense that these bodies act like a comet but don’t light up like a comet — though they are still visible as points of light through a powerful telescope. The assumption is that dark comets are outgassing, but on a barely perceptible level, just enough to give them a push.

Now, another seven dark comets have been identified, bringing the tally to 14 — enough to start drawing some conclusions about their properties.

“We had a big enough number of dark comets that we could begin asking if there was anything that would differentiate them,” said Daryl Seligman of Michigan State University, who led the new research. “By analyzing the reflectivity [of the surface of the dark comets, which is related to their composition] and the orbits, we found that our solar system contains two different types of dark comets.”

One type lurks in the outer solar system, in the realm of the gas and ice giants. The other group is located in the inner solar system, sharing orbits with Mercury, Venus, Earth and Mars. The outer dark comets are larger, with diameters hundreds of meters across or greater, while the inner dark comets are far smaller, measuring tens of meters across, or less.

The outer dark comets have more eccentric, i,.e. elliptical, orbits that are more like those of typical comets, whereas the inner dark comets have more circular orbits like those of the planets. Seligman noted that the outer dark comets have some orbital properties in common with Jupiter-family comets, which are comets that have wandered in from the outermost reaches of the solar system and settled into orbits around the sun that don’t extend much farther out than Jupiter.

The whys and wherefores, however, remain mysterious. How did dark comets come to be in these two locations? In the summer of 2024, Seligman’s team showed how the inner dark comets, at the very least, could have ended up on their current orbits if they were perturbed from their birth zone in the inner region of the asteroid belt.

Related: ‘Dark comets’ may have given Earth its water long ago

Then there’s the question of how much water ice dark comets contain. When the solar system formed 4.5 billion years ago, there was an invisible demarcation called the “snow line.” Inside the snow line, which was just a little bit closer to the sun than where Jupiter is now (about 5 astronomical units — roughly 465 million miles, or 750 million kilometers), temperatures in the protoplanetary disk were too warm for ice to form, and water existed as a vapor or a liquid instead. Beyond the snow line, where the planets of the outer solar system are now, it was cold enough for water to freeze into ice.

So it would not be surprising if the outer dark comets contain ice beneath their surface. But the inner dark comets that seemingly formed inside the snow line must also contain ice, to allow them to outgas and generate thrust for the non-gravitational acceleration. The earlier work of Seligman’s team indicates that as many as 60% of near-Earth objects could be dark comets, which raises the possibility that dark comets impacting on Earth long ago are what brought water to our planet.

“Dark comets are a new potential source for having delivered the materials to Earth that were necessary for the development of life,” said Seligman. “The more we can learn about them, the better we can understand their role in our planet’s origin.”

The discovery of the seven new dark comets was reported on Dec. 9 in the journal Proceedings of the National Academy of Sciences.

Previous Post

Government’s New Climate Target Cements Canada’s Position as a Global Laggard

Next Post

The US Navy wants to use quantum computers for war games and much more todayheadline

Related Posts

Ironheart

Get 76% off, four free months and an Amazon voucher — exclusive deal

June 25, 2025
4
JWST discovers exoplanet through direct imaging

JWST discovers exoplanet through direct imaging

June 25, 2025
5
Next Post
The US Navy wants to use quantum computers for war games and much more

The US Navy wants to use quantum computers for war games and much more todayheadline

  • Trending
  • Comments
  • Latest
Family calls for change after B.C. nurse dies by suicide after attacks on the job

Family calls for change after B.C. nurse dies by suicide after attacks on the job

April 2, 2025
Pioneering 3D printing project shares successes

Product reduces TPH levels to non-hazardous status

November 27, 2024

Police ID man who died after Corso Italia fight

December 23, 2024

Hospital Mergers Fail to Deliver Better Care or Lower Costs, Study Finds todayheadline

December 31, 2024
Harris tells supporters 'never give up' and urges peaceful transfer of power

Harris tells supporters ‘never give up’ and urges peaceful transfer of power

0
Des Moines Man Accused Of Shooting Ex-Girlfriend's Mother

Des Moines Man Accused Of Shooting Ex-Girlfriend’s Mother

0

Trump ‘looks forward’ to White House meeting with Biden

0
Catholic voters were critical to Donald Trump’s blowout victory: ‘Harris snubbed us’

Catholic voters were critical to Donald Trump’s blowout victory: ‘Harris snubbed us’

0
Immigration, pensions, taxes: A look at Alberta Next panel survey questions

Immigration, pensions, taxes: A look at Alberta Next panel survey questions

June 25, 2025
Video: Qassam Brigades releases footage of ambush that killed seven Israeli soldiers

Video: Qassam Brigades releases footage of ambush that killed seven Israeli soldiers

June 25, 2025
Sources: Atlético reach deal for USMNT's Cardoso

Sources: Atlético reach deal for USMNT’s Cardoso

June 25, 2025
Sources: Texas State expecting offer to join Pac-12

Sources: Texas State expecting offer to join Pac-12 todayheadline

June 25, 2025

Recent News

Immigration, pensions, taxes: A look at Alberta Next panel survey questions

Immigration, pensions, taxes: A look at Alberta Next panel survey questions

June 25, 2025
5
Video: Qassam Brigades releases footage of ambush that killed seven Israeli soldiers

Video: Qassam Brigades releases footage of ambush that killed seven Israeli soldiers

June 25, 2025
5
Sources: Atlético reach deal for USMNT's Cardoso

Sources: Atlético reach deal for USMNT’s Cardoso

June 25, 2025
5
Sources: Texas State expecting offer to join Pac-12

Sources: Texas State expecting offer to join Pac-12 todayheadline

June 25, 2025
5

TodayHeadline is a dynamic news website dedicated to delivering up-to-date and comprehensive news coverage from around the globe.

Follow Us

Browse by Category

  • Africa
  • Asia
  • Basketball
  • Business & Finance
  • Climate Change
  • Crime & Justice
  • Cybersecurity
  • Economic Policies
  • Elections
  • Entertainment
  • Entrepreneurship
  • Environmental Policies
  • Europe
  • Football
  • Gadgets & Devices
  • Health
  • Medical Research
  • Mental Health
  • Middle East
  • Motorsport
  • Olympics
  • Politics
  • Public Health
  • Relationships & Family
  • Science & Environment
  • Software & Apps
  • Space Exploration
  • Sports
  • Stock Market
  • Technology & Startups
  • Tennis
  • Travel
  • Uncategorized
  • Us & Canada
  • Wildlife & Conservation
  • World News

Recent News

Immigration, pensions, taxes: A look at Alberta Next panel survey questions

Immigration, pensions, taxes: A look at Alberta Next panel survey questions

June 25, 2025
Video: Qassam Brigades releases footage of ambush that killed seven Israeli soldiers

Video: Qassam Brigades releases footage of ambush that killed seven Israeli soldiers

June 25, 2025
  • Education
  • Lifestyle
  • Technology & Startups
  • About us
  • Contact
  • Advertise with Us
  • Privacy & Policy

© 2024 Todayheadline.co

Welcome Back!

OR

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In
No Result
View All Result
  • Business & Finance
  • Corporate News
  • Economic Policies
  • Entrepreneurship
  • Market Trends
  • Crime & Justice
  • Court Cases
  • Criminal Investigations
  • Cybercrime
  • Legal Reforms
  • Policing
  • Education
  • Higher Education
  • Online Learning
  • Entertainment
  • Awards & Festivals
  • Celebrity News
  • Movies
  • Music
  • Health
  • Fitness & Nutrition
  • Medical Breakthroughs
  • Mental Health
  • Pandemic Updates
  • Lifestyle
  • Fashion & Beauty
  • Food & Drink
  • Home & Living
  • Politics
  • Elections
  • Government Policies
  • International Relations
  • Legislative News
  • Political Parties
  • Africa
  • Asia
  • Europe
  • Middle East
  • Artificial Intelligence
  • Cybersecurity
  • Emerging Technologies
  • Gadgets & Devices
  • Industry Analysis
  • Basketball
  • Football
  • Motorsport
  • Olympics
  • Climate Change
  • Environmental Policies
  • Medical Research
  • Science & Environment
  • Space Exploration
  • Wildlife & Conservation
  • Sports
  • Tennis
  • Technology & Startups
  • Software & Apps
  • Startup Success Stories
  • Startups & Innovations
  • Tech Regulations
  • Venture Capital
  • Uncategorized
  • World News
  • Us & Canada
  • Public Health
  • Relationships & Family
  • Travel
  • Research & Innovation
  • Scholarships & Grants
  • School Reforms
  • Stock Market
  • TV & Streaming
  • Advertise with Us
  • Privacy & Policy
  • About us
  • Contact

© 2024 Todayheadline.co