Sunday, July 12, 2015

New Horizon approaches Pluto

The  New Horizons spacecraft is nearing its encounter with Pluto. New Horizon is a spacecraft with the primary mission to flyby Pluto and collect photographs and other data. The closest approach is expected to occur on Tuesday.

I've discussed the issue of whether Pluto is a planet elsewhere and I don't have much to add except that Alan Stern (the principle investigator of the New Horizons mission) argues that Pluto should be considered a planet. There are differences of opinion on the matter.

If you consider Pluto a planet, Pluto is the only planet which has never been visited by a planet (either landing or flyby). That is until New Horizons.

If you don't, Pluto is still an interesting place. We know very little about Pluto and New Horizons should give us a lot of new data. If fact it already has, and unless there is a major failure it will continue to do so. It will take time to analyze the data, but it is very likely we will have a new understanding of Pluto in the near future.

For more information...

Alan Stern talked about New Horizon and Pluto on NPR's Science Friday (July 10th), see

Dr Stern gave a talk at the University of Michigan in February 2009. This talk discussed Pluto and the solar system; for a description of this talk see .

See also see this page from NASA:

Wednesday, July 8, 2015

Save the date: a pulsar and a giant star are due to meet in 2018

This is going to be a highly anticipated meeting with plenty of fireworks, though be glad we are far enough away to enjoy the view safely.

Pulsars are rotating neutron stars, the leftover remnants of stars that once shone and were more massive than our sun. Pulsars "pulse" because they emit highly directional "beams" of electromagnetic energy from their poles, and we detect this every time they rotate and the beam crosses our path. This can happen thousands of times per second, making them excellent timekeepers!

Stars come in different sizes, and the one of interest in 2018 is about 15 times as massive as our sun. It is in the constellation Cygnus and is about 5,000 light years away from us. This star has a binary companion, a pulsar, that will actually move through its outer atmosphere in 2018. The orbit is fairly long at 25 years.

Check out the NASA press release for more information.