News / Science & Technology

Astronomers Discover New Moon Orbiting Pluto

Two images, taken about a week apart by NASA's Hubble Space Telescope, show four moons orbiting the distant, icy dwarf planet Pluto
Two images, taken about a week apart by NASA's Hubble Space Telescope, show four moons orbiting the distant, icy dwarf planet Pluto
Jessica Berman

Astronomers have discovered a fourth moon orbiting the solar-system's distant dwarf-planet, Pluto.  The speck of rock was spotted by the Hubble space telescope.

The new moon, so far known simply as "P4," is the tiniest of four satellites orbiting Pluto, a sphere of ice and rock smaller than Earth's moon that circles the Sun at a distance of more than five billion kilometers.  P4 was discovered while astronomers were searching, unsuccessfully, for rings around Pluto, which lost its official ranking as the solar-system's ninth planet in 2006.  

Mark Showalter, with the US space agency’s SETI Institute in Mountain View, California, led the team that discovered P4.

Showalter says that when scientists first observed the tiny moon in late June, astronomers thought P4 might be either Nix or Hydra, Pluto’s other smaller moons.

But further observations revealed that the object was a new moon, and an extremely small one - about 13 to 34 kilometers in diameter.

“The reason there’s such a big uncertainty [about] its size is that it all kind of depends on how bright the surface is," said Showalter. "If it’s a fairly bright surface, then it would be a smaller object.  If it’s a fairly dark body, like some of the distant outer solar objects are very, very dark, then it would have to be the larger size.  If you consider those are still remarkably small objects when you consider we are seeing it from three billion miles [4.8 Billion kilometers] away.”

Showalter says P4 is about 10 percent as bright as Nix, which was previously Pluto’s smallest moon.  

Pluto and its largest satellite Charon, which is approximately one thousand kilometers in diameter, form one of two so-called binary systems in our solar system.  The other is the earth-moon system.   

Astronomers believe such double systems were created by massive planetary impacts more than four billion years ago when the solar system was formed.  In the case of Earth, scientists believe a planet about the size of Mars collided with Earth to create our moon.

Showalter says the discovery of P4 suggests Pluto is a dynamic planetary system.

“And of course the mere fact that we have found something new raises the possibility that we should look even a little deeper to see what else might have been overlooked all these years," he said.

The latest discoveries set the stage for NASA’s New Horizons mission, which is scheduled to fly through the Pluto system in 2015.

You May Like

IS Militants Release 49 Turkish Hostages

Turkey's state-run Anadolu news agency reports that no ransom was paid and no conditions accepted for the hostages' release; few details of the release are known More

Photogallery IS Attacks Send Thousands of Syrian Kurds Fleeing to Turkey

Syrian Observatory for Human Rights says more than 300 Kurdish fighters crossed into Syria from Turkey to defend a Kurdish area from attack by the Islamic militants More

Video Sierra Leone's Ebola Lockdown Continues

Thousands of health workers are going door to door in the West African country of 6 million, informing people of how to avoid Ebola, handing out soap More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Fears Ebola Outbreak ‘Beyond Our Capability to Contain’i
X
Jeff Seldin
September 20, 2014 10:28 PM
Each day brings with it new warnings about the deadly Ebola outbreak already blamed for killing more than 2,600 people across West Africa. And while countries and international organizations like the United Nations are starting to come through on promises of help for those most affected, the unprecedented speed with which the virus has spread is raising questions about the international response. VOA's Jeff Seldin has more from Washington.
Video

Video Fears Ebola Outbreak ‘Beyond Our Capability to Contain’

Each day brings with it new warnings about the deadly Ebola outbreak already blamed for killing more than 2,600 people across West Africa. And while countries and international organizations like the United Nations are starting to come through on promises of help for those most affected, the unprecedented speed with which the virus has spread is raising questions about the international response. VOA's Jeff Seldin has more from Washington.
Video

Video Iran, World Powers Seek Progress in Nuclear Talks

Iran and the five permanent members of the U.N. Security Council plus Germany, known as the P5 + 1, have started a new round of talks on Iran's nuclear program. VOA State Department correspondent Pam Dockins reports that as the negotiations take place in New York, a U.S. envoy is questioning Iran's commitment to peaceful nuclear activity.
Video

Video Obama Goes to UN With Islamic State, Ebola on Agenda

President Obama goes to the United Nations General Assembly to rally nations to support a coalition against Islamic State militants in Iraq and Syria. He also will look for nations to back his plan to fight the Ebola virus in West Africa. As VOA White House correspondent Luis Ramirez reports, Obama’s efforts reflect new moves by the U.S. administration to take a leading role in addressing world crises.
Video

Video Migrants Caught in No-Man's Land Called Calais

The deaths of hundreds of migrants in the Mediterranean this week has only recast the spotlight on the perils of reaching Europe. And for those forunate enough to reach a place like Calais, France, only find that their problems aren't over. Lisa Bryant has the story.
Video

Video Westgate Siege Anniversary Brings Back Painful Memories

One year after it happened, the survivors of the terror attack on Nairobi's Westgate Shopping Mall still cannot shake the images of that tragic incident. For VOA, Mohammed Yusuf tells the story of victims still waiting for the answer to the question 'how could this happen?'
Video

Video Militant Assault in Syria Displaces Thousands of Kurds

A major assault by Islamic State militants on Kurds in Syria has sent a wave of new refugees to the Turkish border, where they were stopped by Turkish border security. Turkey is already hosting about 700,000 Syrian refugees who fled the civil war between the government and the opposition. But the government in Ankara has a history of strained relations with Turkey's Kurdish minority. Zlatica Hoke reports Turkey is asking for international help.
Video

Video Whaling Summit Votes to Uphold Ban on Japan Whale Hunt

The International Whaling Commission, meeting in Slovenia, has voted to uphold a court ruling banning Japan from hunting whales in the Antarctic Ocean. Conservationists hailed the ruling as a victory, but Tokyo says it will submit revised plans for a whale hunt in 2015. Henry Ridgwell reports from London.
Video

Video A Dinosaur Fit for Land and Water

Residents and tourists in Washington D.C. can now examine a life-size replica of an unusual dinosaur that lived almost a hundred million years ago in northern Africa. Scientists say studying the behemoth named Spinosaurus helps them better understand how some prehistoric animals adapted to life on land and in water. The Spinosaurus replica is on display at the National Geographic museum. VOA’s George Putic has more.
Video

Video Iraqi Kurdistan Church Helps Christian Children Cope find shelter in churches in the Kurdish capital, Irbil

In the past six weeks, tens of thousands of Iraqi Christians have been forced to flee their homes by Islamic State militants and find shelter in churches in the Kurdish capital, Irbil. Despite U.S. airstrikes in the region, the prospect of people returning home is still very low and concerns are starting to grow over the impact this is having on the displaced youth. Sebastian Meyer reports from Irbil on how one church is coping.


Carnage and mayhem are part of daily life in northern Nigeria, the result of a terror campaign by the Islamist group Boko Haram. Fears are growing that Nigeria’s government may not know how to counter it, and may be making things worse. More

AppleAndroid