a new planet

This is very exciting: astronomers at the University of Toronto have spotted a planet.

Young star 1RXS J160929.1-210524 and its faint, planetary mass candidate companion.

University of Toronto astronomers have unveiled what is likely the first picture of a planet around a star similar to the sun.

Three scientists from astronomy and astrophysics used the Gemini North telescope on Mauna Kea in Hawaii to take images of the young star 1RXS J160929.1-210524 (which lies outside the solar system at about 500 light-years from Earth) and a candidate companion of that star. They also obtained spectra to confirm the nature of the companion, which has a mass about eight times that of Jupiter and lies roughly 330 times the Earth-sun distance away from its star. (For comparison, the most distant planet in our solar system, Neptune, orbits the sun at only about 30 times the Earth-sun distance.) The parent star is similar in mass to the sun but is much younger.

"This is the first time we have directly seen a planetary mass object in a likely orbit around a star like our sun," said David Lafrenicre, a post-doctoral fellow and lead author of a paper submitted to the Astrophysical Journal Letters and also posted online. "If we confirm that this object is indeed gravitationally tied to the star, it will be a major step forward."

Actually I think I heard about this when it happened and forgot to look it up. But anyway, a planet like ours near a star like ours. Wow - it could be capable of supporting life.

Hat-tip to Geekologie.

More information and a bigger picture on Astronomy Picture of the Day.

a matter for divorce

I'd have divorced him too. Sizeist.

Fortunately, in our house, we are as one: Pluto is a planet. And Chiron, and Sedna....

arts graduates

Dawkins is wrong, wrong, wrong. The enemy of science is not religion, it's arts graduates. (Well actually it's probably corporate greed, but today it's arts graduates.)

On the Today programme on Radio 4 this morning, there was an item about the acquisition of an important meteorite by the Natural History Museum. One of the presenters said they didn't know the difference between a comet and a meteor, and everyone else in the studio said that they didn't either. If they had said they didn't know the difference between a meteor and a meteorite, that would have been fair enough. Or even if they had been embarrassed about not knowing - but no, they were quite pleased with themselves!

I expect they would laugh at people who didn't know the difference between, say, Cézanne and Monet; but they seem to think it's fine not to understand a fairly basic piece of science. Nor is this a one-off incident; similar things have happened several times on the Today programme (like the time someone felt the need to point out that the Earth orbits the Sun).

It's simple really - a comet is a big ball of dirt and ice which has an elliptical orbit around the sun, which acquires a tail and a coma due to the ice melting as it gets closer to the sun; and a meteor is a shooting star (a small piece of space debris, often a fragment of asteroid) that has a decaying orbit and gets caught in the Earth's gravitational field and burns up on entry to the atmosphere.

Balador checked that the above was correct by going to a helpful NASA FAQ page, which has a neat little table:

Asteroid	A relatively small, inactive, rocky body orbiting the Sun.
Comet	A relatively small, at times active, object whose ices can vaporize in sunlight forming an atmosphere (coma) of dust and gas and, sometimes, a tail of dust and/or gas.
Meteoroid	A small particle from a comet or asteroid orbiting the Sun.
Meteor	The light phenomena which results when a meteoroid enters the Earth's atmosphere and vaporizes; a shooting star.
Meteorite	A meteoroid that survives its passage through the Earth's atmosphere and lands upon the Earth's surface.

tender is the night

Astronomy Picture of the Day has a photo of the night as we should all be seeing it, if only street lighting didn't cause so much light pollution.

I was lucky enough to see the stars like this once, on a visit to Dumfries and Galloway - but it should be available to everyone, everywhere - it's just a matter of putting proper shades on the streetlamps, which would direct more light down onto the street where it's needed, and probably save energy into the bargain.

the darkness at the end of the paradigm

The other day we went to a very thought-provoking talk by Jocelyn Bell Burnell (the discoverer of pulsars) at the Bath Science Café at The Raven.

There was talk of dark matter and dark energy, which are basically 'dark' in the sense that no-one knows what they are. We do know that dark matter is probably non-baryonic, unlike most matter in the universe. (Baryonic matter is matter with protons and neutrons in the nucleus.)

So, she said, there will be a paradigm shift when the nature of dark matter and dark energy is discovered.

There was a similar paradigm shift when it was finally realised that phlogiston didn't exist. Natural philosophers studying burning materials assumed that, since they gained weight after burning, they must be emitting a substance that had negative mass; they called this substance phlogiston. Joseph Priestley almost had it right when he produced "phlogisticated air" (air that, he believed, was rich in phlogiston), but it was Antoine Lavoisier who realised that phlogiston didn't exist, and that rather than losing a substance with negative mass, the burning material was actually fixing oxygen out of the air. The theory of phlogiston may seem daft now, but it made sense at a time when it was assumed that air was all one substance, not several different gases mixed together. (I remember watching a video about this in O-level Chemistry.)

Another paradigm shift that Professor Bell Burnell told us about occurred in astronomy when looking at planetary orbits; it was assumed they were circular, but then people observed anomalies in them and called them epicycles, and it all got very untidy until Johannes Kepler pointed out that the orbits were elliptical.

And of course the most famous paradigm shift of all was the one when Copernicus pointed out that we live in a heliocentric solar system, not a geocentric one.

At least nowadays you are not likely to get burnt at the stake or kept under house arrest for suggesting a radical new scientific idea. The worst thing that could happen to you is loss of tenure.

The point of all this is to say that, although there is speculation as to what dark matter and dark energy might be, it may be that something else is wrong, such as the basic assumptions which led to the need to theorise their existence, in which case whatever is causing the need to insert them into the theoretical models turns out to be something completely different. In a hundred years' time, people could be laughing at those early 21st century scientists who believed in 'dark matter' and 'dark energy', in the same way that we find phlogiston, flat earth theory and geocentric cosmology amusing nowadays. Such is the weirdness when we're sitting on the brink of a paradigm shift. Maybe a bit like sitting at the event horizon of a black hole - nothing will ever be the same again once you have passed the threshold.