Featured Research

from universities, journals, and other organizations

Pioneer anomaly solved? Interstellar travelers of the future may be helped by physicist's calculations

Date:
October 9, 2012
Source:
University of Missouri-Columbia
Summary:
Interstellar travel will depend upon extremely precise measurements of every factor involved in the mission. The knowledge of those factors may be improved by a researcher's solution, found to a puzzle that has stumped astrophysicists for decades.

An artist's view of a Pioneer spacecraft heading into interstellar space. Both Pioneer 10 and 11 are on trajectories that will eventually take them out of our solar system.
Credit: NASA

Interstellar travel will depend upon extremely precise measurements of every factor involved in the mission. The knowledge of those factors may be improved by the solution a University of Missouri researcher found to a puzzle that has stumped astrophysicists for decades.

"The Pioneer spacecraft, two probes launched into space in the early 70s, seemed to violate the Newtonian law of gravity by decelerating anomalously as they traveled, but there was nothing in physics to explain why this happened," said Sergei Kopeikin, professor of physics and astronomy in MU's College of Arts and Science. "My study suggests that this so-called Pioneer anomaly was not anything strange. The confusion can be explained by the effect of the expansion of the universe on the movement of photons that make up light and radio waves."

Beams of radio waves were sent to and bounced off the Pioneer spacecraft to measure the probes' movement. The time it took for the photons to complete a round trip was used to calculate the spacecrafts' distance and speed. Kopeikin's research suggests that the photons move faster than expected from the Newtonian theory thus causing the appearance of deceleration, though the craft were actually traveling at the correct speed predicted by the theory. The universe is constantly expanding and this alters the Earth-based observations of the photons bouncing off the spacecraft, causing the Pioneer probes to appear to slow down.

"Previous research has focused on mechanical explanations for the Pioneer anomaly, such as the recoil of heat from the craft's electrical generators pushing the craft backwards," Kopeikin said. "However that only explains 15 to 20 percent of the observed deceleration, whereas it is the equation for photons that explains the remaining 80-85 percent."

Physicists must be careful when dealing with propagation of light in the presence of the expansion of space, noted Kopeikin, since it is affected by forces that are irrelevant in other equations. For example, the expansion of the universe affects photons, but doesn't influence the motion of planets and electrons in atoms.

"Having accurate measurements of the physical parameters of the universe help us form a basis to make plans for interstellar exploration," Kopeikin said. "Discerning the effect of the expansion of the universe on light is important to the fundamental understanding of space and time. The present study is part of a larger on-going research project that may influence the future of physics."

The study "Celestial ephemerides in an expanding universe," was published in the journal Physical Review D.


Story Source:

The above story is based on materials provided by University of Missouri-Columbia. Note: Materials may be edited for content and length.


Journal References:

  1. Sergei Kopeikin. Celestial ephemerides in an expanding universe. Physical Review D, 2012; 86 (6) DOI: 10.1103/PhysRevD.86.064004
  2. Sergei Kopeikin. Celestial ephemerides in an expanding universe. Physical Review D, 2012; 86 (6) DOI: 10.1103/PhysRevD.86.064004

Cite This Page:

University of Missouri-Columbia. "Pioneer anomaly solved? Interstellar travelers of the future may be helped by physicist's calculations." ScienceDaily. ScienceDaily, 9 October 2012. <www.sciencedaily.com/releases/2012/10/121009161103.htm>.
University of Missouri-Columbia. (2012, October 9). Pioneer anomaly solved? Interstellar travelers of the future may be helped by physicist's calculations. ScienceDaily. Retrieved August 28, 2014 from www.sciencedaily.com/releases/2012/10/121009161103.htm
University of Missouri-Columbia. "Pioneer anomaly solved? Interstellar travelers of the future may be helped by physicist's calculations." ScienceDaily. www.sciencedaily.com/releases/2012/10/121009161103.htm (accessed August 28, 2014).

Share This




More Space & Time News

Thursday, August 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

SpaceX’s Falcon 9 Rocket Explodes After Liftoff

SpaceX’s Falcon 9 Rocket Explodes After Liftoff

Newsy (Aug. 23, 2014) The private spaceflight company says it is preparing a thorough investigation into Friday's mishap. Video provided by Newsy
Powered by NewsLook.com
Did Russia Really Find Plankton On The ISS? NASA Not So Sure

Did Russia Really Find Plankton On The ISS? NASA Not So Sure

Newsy (Aug. 21, 2014) Russian cosmonauts say they've found evidence of sea plankton on the International Space Station's windows. NASA is a little more skeptical. Video provided by Newsy
Powered by NewsLook.com
Space to Ground: Hello Georges

Space to Ground: Hello Georges

NASA (Aug. 18, 2014) Europe's ATV-5 delivers new science and the crew tests smart SPHERES. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com
Tiny Satellites, Like The One Tossed From ISS, On The Rise

Tiny Satellites, Like The One Tossed From ISS, On The Rise

Newsy (Aug. 18, 2014) The Chasqui I, hand-delivered into orbit by a Russian cosmonaut, is one of hundreds of small satellites set to go up in the next few years. Video provided by Newsy
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:
from the past week

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