Milky Way Likely Has Tens of Billions of Rocky 'Super-Earths'

Stars in the Milky Way galaxy (file photo)
Stars in the Milky Way galaxy (file photo)

Astronomers at the European Southern Observatory (ESO) say new data indicates there is an abundance of rocky Super-Earth-type planets orbiting in the habitable zones of a common type of star known as a red dwarf.  They estimate there are tens of billions within our Milky Way galaxy alone.

Super-earth is the term astronomers use to describe a type of rocky planet outside our solar system - an exoplanet - that measures less than 10 times the mass of the Earth.

The ESO astronomers say their calculations show that about 40 percent of all red dwarf stars have a super-Earth orbiting within a habitable zone where liquid water can exist on the surface of the planet - the best indicator for the possibility of extraterrestrial life.

The researchers made the new findings from data collected with the planet-finding HARPS spectrograph at ESO’s La Silla observatory in Chile.  They say HARPS’ observations provided the first direct measurement of the frequency of super-Earths orbiting red dwarf stars.  

Red dwarfs are small, cool stars that have an extraordinarily long evolutionary life, and therefore are very common.  They comprise an estimated 80 percent of the stars in the Milky Way - that amounts to around 160 billion red dwarfs.   

The results of a separate study announced earlier this year indicated that rocky Earth-like worlds far outnumber massive gas-giant planets in the Milky Way galaxy.

The new ESO study will be published in the journal, Astronomy and Astrophysics.

Red dwarfs may be among the most ubiquitous of stars in the cosmos, but our relatively young, bright, yellow Sun is not one of them.

The Milky Way galaxy has a diameter of approximately 120,000 light years.  That means it would take 120,000 years for light to travel across the galaxy.  The speed of light is 300,000 kilometers per second.

This forum has been closed.
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.
With HIV, Can We Get to Zero?i
Carol Pearson
November 29, 2015 1:23 PM
The theme of this year's World AIDS Day is "Getting to Zero." The U.N. says new HIV infections have been reduced by 35 percent since 2000 and AIDS-related deaths are down by 42 percent since the peak in 2004. VOA's Carol Pearson takes a look at what it might take to actually have an AIDS-free generation.

Video With HIV, Can We Get to Zero?

The theme of this year's World AIDS Day is "Getting to Zero." The U.N. says new HIV infections have been reduced by 35 percent since 2000 and AIDS-related deaths are down by 42 percent since the peak in 2004. VOA's Carol Pearson takes a look at what it might take to actually have an AIDS-free generation.

Video Political Motives Seen Behind Cancelled Cambodian Water Festival

For the fourth time in the five years since more than 350 people were killed in a stampede at Cambodia’s annual water festival, authorities canceled the event this year. Officials blamed environmental reasons as the cause, but many see it as fallout from rising political tensions with a fresh wave of ruling party intimidation against the opposition. David Boyle reports from Phnom Penh.

Video African Circus Gives At-Risk Youth a 2nd Chance

Ethiopia hosted the first African Circus Arts Festival this past weekend with performers from seven different African countries. Most of the performers are youngsters coming form challenging backgrounds who say the circus gave them a second chance.

Video US Lawmakers Brace for End-of-Year Battles

U.S. lawmakers are returning to Washington for Congress’ final working weeks of the year. And, as VOA's Michael Bowman reports, a full slate of legislative business awaits them, from keeping the federal government open to resolving a battle with the White House over the admittance of Syrian refugees.

Video Taiwan Looks for Role in South China Sea Dispute

The Taiwanese government is one of several that claims territory in the hotly contested South China Sea, but Taipei has long been sidelined in the dispute, overshadowed by China. Now, as the Philippines challenges Beijing’s claims in an international court at The Hague, Taipei is looking to publicly assert its claims. VOA’s Bill Ide has more from Beijing.

Video After Terrorist Attacks, Support for Refugees Fades

The terrorists who killed and injured almost 500 people around Paris this month are mostly French or Belgian nationals. But at least two apparently took advantage of Europe’s migrant crisis to sneak into the region. The discovery has hardened views about legitimate refugees, including those fleeing the same extremist violence that hit the French capital. Lisa Bryant has this report for VOA from the Paris suburb of Cergy-Pontoise

Video Syrian Refugees in US Express Concern for Those Left Behind

Syrian immigrants in the United States are concerned about the negative tide of public opinion and the politicians who want to block a U.S. plan to accept 10,000 Syrian refugees. Zlatica Hoke reports many Americans are fighting to dispel suspicions linking refugees to terrorists.

Video Thais Send Security Concerns Down the River

As Thailand takes in the annual Loy Krathong festival, many ponder the country’s future and security. Steve Sandford reports from Chiang Mai.

Video Islamic State Unfazed by Losses in Iraq, Syria

Progress in the U.S.-led effort to beat Islamic State on its home turf in Iraq and Syria has led some to speculate the terror group may be growing desperate. But counterterror officials say that is not the case, and warn the recent spate of terror attacks is merely part of the group’s evolution. VOA National Security correspondent Jeff Seldin has more.

Video Belgium-Germany Border Remains Porous, Even As Manhunt For Paris Attacker Continues

One of the suspected gunmen in the Nov. 13 Paris attacks, Salah Abdeslam, evaded law enforcement, made his way to Belgium, and is now believed to have fled to Germany. VOA correspondent Ayesha Tanzeem makes the journey across the border from Belgium into Germany to see how porous the borders really are.

Video US, Cambodian Navies Pair Up in Gulf of Thailand

The U.S. Navy has deployed one of its newest and most advanced ships to Cambodia to conduct joint training drills in the Gulf of Thailand. Riding hull-to-hull with Cambodian ships, the seamen of the USS Fort Worth are executing joint-training drills that will help build relations in Southeast Asia. David Boyle reports for VOA from Preah Sihanouk province.

Video Uncertain Future for Syrian Refugee Resettlement in Illinois

For the trickle of Syrian refugees finding new homes in the Midwest city of Chicago, the call to end resettlement in many U.S. states is adding another dimension to their long journey fleeing war. Organizations working to help them integrate say the backlash since the Paris attacks is both harming and helping their efforts to provide refugees sanctuary. VOA's Kane Farabaugh reports.

VOA Blogs