Featured Research

from universities, journals, and other organizations

Could life have survived a fall to Earth?

Date:
September 12, 2013
Source:
Europlanet Media Centre
Summary:
It sounds like science fiction, but the theory of panspermia, in which life can naturally transfer between planets, is considered a serious hypothesis by planetary scientists. The suggestion that life did not originate on Earth but came from elsewhere in the universe (for instance, Mars), is one possible variant of panspermia. Planets and moons were heavily bombarded by meteorites when the Solar System was young, throwing lots of material back into space. Meteorites made of Mars rock are occasionally found on Earth to this day, so it is quite plausible that simple life forms like yeasts or bacteria could have been carried on them.

Asteroid impacting Earth's oceans.
Credit: NASA/Don Davis

It sounds like science fiction, but the theory of panspermia, in which life can naturally transfer between planets, is considered a serious hypothesis by planetary scientists. The suggestion that life did not originate on Earth but came from elsewhere in the universe (for instance, Mars), is one possible variant of panspermia. Planets and moons were heavily bombarded by meteorites when the Solar System was young, throwing lots of material back into space. Meteorites made of Mars rock are occasionally found on Earth to this day, so it is quite plausible that simple life forms like yeasts or bacteria could have been carried on them.

Related Articles


Yet serious questions remain for supporters of this theory. Would even the hardiest life forms be able to survive an impact which ejects the rock into space? Could they live through the freezing temperatures and deadly radiation of space? And could they enter the atmosphere and hit the surface of Earth without being killed?

New research presented at the European Planetary Science Congress at UCL aims to answer the final question, of whether entry and impact is survivable for simple organisms. Using frozen samples of Nannochloropsis oculata, a type of single-celled ocean-dwelling algae, Dina Pasini (University of Kent) set out to test the conditions which early life would have had to survive if it did indeed travel through space.

Using a two-stage light gas gun, which can accelerate objects up to very high speeds, Pasini fired frozen pellets of Nannochloropsis into water, and tested the samples to see if any had survived.

"As you might expect, increasing the speed of impact does increase the proportion of algae that die," Pasini explains, "but even at 6.93 kilometres per second, a small proportion survived. This sort of impact velocity would be what you would expect if a meteorite hit a planet similar to the Earth."

As well as surviving freezing and impacts, like those experienced when rocks are ejected from planets or hit them, there are good reasons to think that the other problems faced by panspermia are not insurmountable either. Ice and rocks can provide protection against radiation, especially if the organism is deeply embedded inside. What is more, heating caused by entry into the atmosphere is unlikely to heat anything more than a thin layer around the outside of rocks, forming what is known as a 'fusion crust'.

This research suggests that panspermia, while certainly not proven, is not impossible either.

"Our research raises several questions," Pasini says. "If we find life on another planet, will it be truly alien or will it be related to us? And if so, did it spawn us or did we spawn it? We cannot answer these questions just now, but the questions are not as farfetched as one might assume."


Story Source:

The above story is based on materials provided by Europlanet Media Centre. Note: Materials may be edited for content and length.


Cite This Page:

Europlanet Media Centre. "Could life have survived a fall to Earth?." ScienceDaily. ScienceDaily, 12 September 2013. <www.sciencedaily.com/releases/2013/09/130912092731.htm>.
Europlanet Media Centre. (2013, September 12). Could life have survived a fall to Earth?. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2013/09/130912092731.htm
Europlanet Media Centre. "Could life have survived a fall to Earth?." ScienceDaily. www.sciencedaily.com/releases/2013/09/130912092731.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Space & Time News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Scientists Find Invisible Space Shield Protecting Earth

Scientists Find Invisible Space Shield Protecting Earth

Newsy (Nov. 27, 2014) An invisible barrier is keeping dangerous super fast electrons from interfering with our atmosphere, but scientists aren't entirely sure how. Video provided by Newsy
Powered by NewsLook.com
NASA's First 3-D Printer In Space Creates Its First Object

NASA's First 3-D Printer In Space Creates Its First Object

Newsy (Nov. 26, 2014) The International Space Station is now using a proof-of-concept 3D printer to test additive printing in a weightless, isolated environment. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Soyuz Spacecraft Docks With International Space Station: NASA

Soyuz Spacecraft Docks With International Space Station: NASA

AFP (Nov. 24, 2014) A Russian Soyuz spacecraft carrying Italy's first female astronaut safely docks with the International Space Station, according to NASA. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins