Spinning stars help scientists 'weigh' planets in our Solar System

Washington, Aug 24 (ANI): An international team of researchers has come up with a new way to weigh the planets in our Solar System, using radio signals from pulsars.

Data from a set of four pulsars have been used to weigh Mercury, Venus, Mars, Jupiter and Saturn with their moons and rings.

The new measurement technique, developed by lead author David Champion, now at Max Planck Institute for Radio Astronomy in Bonn, with researchers from Australia, Germany, the U.S., U.K. and Canada, is sensitive to just 0.003 percent of the mass of the Earth, and one ten-millionth of Jupiter's mass (corresponding to a mass difference of two hundred thousand million million tons).

Until now, astronomers have weighed planets by measuring the orbits of their moons or of spacecraft flying past them.

That's because mass creates gravity, and a planet's gravitational pull determines the orbit of anything that goes around it-both the size of the orbit and how long it takes to complete.

The new method is based on corrections astronomers make to signals from pulsars, small spinning stars that deliver regular "blips" of radio waves. Measurements of planet masses made this new way could feed into data needed for future space missions.

"This is first time anyone has weighed entire planetary systems-planets with their moons and rings," said team leader Dr. David Champion of the Max Planck Institute for Radio Astronomy.

"In addition, we can provide an independent check on previous results, which is great for planetary science," he added.

The results are described in an article for the "Astrophysical Journal." (ANI)