Artist’s impression of Earth-like planet (Credit: difference.weblog.glam.ac.uk)
A newly discovered planet in a binary star system located 3,000 light-years from Earth is expanding astronomers’ notions of where Earth-like — and even potentially habitable — planets can form, and how to find them.
At twice the mass of Earth, the planet orbits one of the stars in the binary system at almost exactly the same distance from which Earth orbits the Sun. However, because the planet’s host star is much dimmer than the Sun, the planet is much colder than the Earth — a little colder, in fact, than Jupiter’s icy moon Europa.
Four international research teams, led by professor Andrew Gould of The Ohio State University, published their discovery in the July 4 issue of the journal Science [http://www.sciencemag.org].
The study provides the first evidence that terrestrial planets can form in orbits similar to Earth’s, even in a binary star system where the stars are not very far apart. Although this planet itself is too cold to be habitable, the same planet orbiting a Sun-like star in such a binary system would be in the so-called “habitable zone” — the region where conditions might be right for life.
“This greatly expands the potential locations to discover habitable planets in the future,” said Scott Gaudi, professor of astronomy at Ohio State. “Half the stars in the galaxy are in binary systems. We had no idea if Earth-like planets in Earth-like orbits could even form in these systems. ” Continue reading
Crops grown on “land-grabbed” areas in developing countries could have the potential to feed an extra 100 million people worldwide, a new study has shown.
Environmental Research Letters
The improved infrastructure brought about by foreign investment could increase the productivity of subsistence farmlands in countries such as Indonesia and Papua New Guinea and could mean these lands can feed at least 300 million people around the world. This is compared to about 190 million people that could be fed if the land was left tended to by the local population.
The findings have been published today, 27 June, in IOP Publishing’s journal Environmental Research Letters. Continue reading
Work presented today at the Goldschmidt Geochemistry Conference in Sacramento, California, shows that the timing of the giant impact between Earth’s ancestor and a planet-sized body occurred around 40 million years after the start of solar system formation. This means that the final stage of Earth’s formation is around 60 million years older than previously thought.
Geochemists from the University of Lorraine in Nancy, France, have discovered an isotopic signal which indicates that previous age estimates for both the Earth and the Moon are underestimates. Looking back into “deep time” it becomes more difficult to put a date on early Earth events. In part this is because there is little “classical geology” dating from the time of the formation of the Earth — no rock layers, etc. So geochemists have had to rely on other methods to estimate early Earth events. One of the standard methods is measuring the changes in the proportions of different gases (isotopes) which survive from the early Earth. Continue reading
Moon (Source: greeksky.gr)
A group of scientists believe that a previously unexplained isotopic ratio from deep within the Earth may be a signal from material from the time before the Earth collided with another planet-sized body, leading to the creation of the Moon. This may represent the echoes of the ancient Earth, which existed prior to the proposed collision 4.5 billion years ago. This work is being presented at the Goldschmidt conference in Sacramento, California. Continue reading
A new series of measurements of oxygen isotopes provides increasing evidence that the Moon formed from the collision of the Earth with another large, planet-sized astronomical body, around 4.5 billion years ago. This work will be published in Science* on 6th June, and will be presented to the Goldschmidt geochemistry conference in California on 11th June. Continue reading