Life could possibly evolve on a neutron star itself as “hyper-dense microscopic organisms controlled by nuclear forces with a metabolism faster than ordinary chemical-based life,” suggests Lord Martin Rees, Britain’s acclaimed Astronomer Royal and Cambridge University physicist.
“Even if simple life is common, it is a separate question whether it’s likely to evolve into anything we might recognize as intelligent or complex – and where this might happen.” Rees adds. But he warns: “If there’s advanced life elsewhere we must not be too anthropomorphic about it. It may be something that we would not recognize.”
Not so oddly, radio astronomer Frank Drake (of Drake’s Equation fame) has suggested that intelligent life could inhabit neutron stars, which inspired science-fiction author Robert Forward’s classic, Dragon’s Egg, that developed Drake’s theory that such creatures would be microscopic. It’s a story of sacrifice and triumph, human scientists establish a relationship with intelligent lifeforms–the cheela–living on Dragon’s Egg, a neutron star where one Earth hour is equivalent to hundreds of their years. The cheela culturally evolve from savagery to the discovery of science, and for a brief time, humans are their diligent teachers.
In 1991, radio signals from the pulsar PSR B1257+12 in the constellation Virgo led Penn State professor of Astronomy and Astrophysics Alexander Wolszczan to the discovery of the first planets ever known outside our solar system.
Wolszczan used the worlds largest radio telescope in Arecibo, Puerto Rico, to time the radio signals coming from a distant tiny neutron star in the constellation Virgo, 7,000 trillion miles from Earth. These measurements helped him to determine that two of the planets are similar in mass to Earth and the other is about the mass of the Moon.
In 2011, a former white dwarf star was discovered transformed into a planet made of diamonds while circling a rapidly spinning pulsar. This dazzling discovery was made using the 64 meter Parkes radio telescope in Australia where irregularities in the signal from the pulsar alerted astronomers that something was orbiting it. After follow up observations were made with the Lovell radio telescope in the UK and one of the Keck telescopes in Hawaii, the international team realized that there is something very unusual about this mysterious object.
Until Wolszczan’s discovery, the only known planets were in our solar system. The planets Wolszczan found probably don’t support life because the tiny pulsar they orbit bombards them with deadly radiation.
The neutron star Wolszcan discovered is the remnant of a supernova explosion–with a mass larger than the Sun’s compressed within a radius of 10 kilometers with density 100 trillion times higher than an ordinary solid.
The radiation neutron stars emit is exponentially brighter than a terrestrial laser and its magnetic fields are millions times more intense than what can be created in Earth-based labs along with gravity a 1000 billion times stronger than on Earth.
Wolszczan’s neutron star radiates little light, but it emits penetrating x -rays and ejects winds at nearly the speed of light. Astronomers are baffled at how this planetary system got there. But current thinking is that the earlier star had its own system of planets before its supernova phase. The three remaining planets existed on the outer orbits, possibly with life forms that would have been snuffed out by the vaporizing blast of the supernova.
All three pulsar planets are shown in the image below; the farthest two from the pulsar (closest in this view) are about the size of Earth. Radiation from charged pulsar particles would probably rain down on the planets, causing their night skies to light up with auroras similar to our Northern Lights. One such aurora is illustrated on the planet at the bottom of the picture.
Since this landmark discovery, more than 160 extrasolar planets have been observed around stars that are burning nuclear fuel. The planets spotted by Wolszczan might be part of a second generation of planets, the first having been destroyed when their star blew up. The Spitzer Space Telescope’s discovery of a dusty disk around a pulsar might represent the beginnings of a similarly “reborn” planetary system.
A team led by Roberto Mignani from INAF Milan (Italy) and from the University of Zielona Gora (Poland), used ESO’s Very Large Telescope (VLT) at the Paranal Observatory in Chile to observe the neutron star RX J1856.5-3754, about 400 light-years from Earth shown at top of the page. Despite being amongst the closest neutron stars, its extreme dimness meant the astronomers could only observe the star with visible light using the FORS2 instrument on the VLT, at the limits of current telescope technology. (spaceengine.org and ESO)
Via NASA/JPL and astro.psu.edu
Image Credit:NASA/JPL-Caltech and NASA/CXC/ S. KUMAR AND S. SAFI–HARB