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 http://www.sciencefriday.com/

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 http://www.lowbrows.org/reflections/2009/dwarshow.5.html .

See also see this page from NASA: http://www.nasa.gov/feature/latest-images-of-pluto-from-new-horizons

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.

Friday, April 10, 2015

University of Michigan to help build next-generation dark energy probe

Update to blog post of Thursday, September 5, 2013 ( http://lowbrows.blogspot.com/2013/09/we-may-be-able-to-watch-dark-energy.html )

University of Michigan to help build next-generation dark energy probe
By Aimee Balfe (Department of Astronomy) and Carol Rabuck (Department of Physics)

University of Michigan scientists and students will build components of a giant camera that will map 30 million galaxies' worth of the universe in three dimensions.


The camera is officially known as the Dark Energy Spectroscopic Instrument (DESI) and it's designed to help answer one of the most puzzling scientific questions of our time: Why is the expansion of the universe accelerating?
To read the rest of the article, go to: http://record.umich.edu/articles/u-m-help-build-next-generation-dark-energy-probe

Wednesday, March 4, 2015

Help name an exoplanet

Last year, the International Astronomical Union (IAU for short) decided that exoplanets deserve names. The IAU is the organization responsible for assigning names to astronomical objects and for demoting Pluto from a planet to a dwarf-planet.

Exoplanets are planets in orbit around stars other than our own sun. Over the past decade, hundreds of exoplanets have been discovered. The hope: exoplanets similar to the earth will eventually be discovered, planets that might be capable of supporting life. In fact we've discovered a wide variety of exoplanets, but we haven't found life beyond our solar system.

Individuals like you can be part of the process of naming one of these exoplanets. For now everyone must go through an official IAU astronomical organization. At the time of this post, there are two such organizations in the Ann Arbor area, the Ann Arbor Hands Museum and the University Lowbrow Astronomers. If you want to participate now you should look at the rules for this process (see the following web site)...

http://www.nameexoworlds.org/the_process

If you want to work through the Lowbrows, please leave a suggested name along with a short reason why you think it is an good name for a planet as a comment on this post. We will go through the comments, we are allowed to submit one name, so we will pick what we consider to be the best name and submit it.

You can also go to https://directory.iau.org/directory to find other organizations to work with.

Over the next few months suggested names will be send to the IAU by the Lowbrows and other organizations. Sometime this summer, all interested parties will be allowed to vote on the different names that the IAU has received.

Wednesday, January 28, 2015

Barns Are Painted Red Because of the Physics of Dying Stars

http://www.smithsonianmag.com/smart-news/barns-are-painted-red-because-of-the-physics-of-dying-stars-58185724/?no-ist

I like articles such as this one that take mundane phenomena and link them to the stars. Though worth a read, punchline / TL;DR of this is that nuclear fusion stops generating excess energy at iron and this leads to an abundance of iron seeding the universe following supernovae, finding its way to rocky planets such as ours. Thus, iron oxide is plentiful, cheap, and just happens to make red paint.

Monday, January 19, 2015

Rare Triple Shadow Transit on January 23/January 24.

During the evening of Friday January 23/Saturday January 24 there will be a triple shadow transit. This is a rare occurrence where three of Jupiter's moons (Europa, Callisto and Io) pass between Jupiter and the Earth. For a period of time the shadow of the three moons will be visible on Jupiter's disk.

This is easy to observe with a small telescope, provided it is clear and dark at your location while the transit is taking place. For observers in the eastern United States (in the Eastern time zone) here is the timing....

Friday January 23 22:09 Callisto's shadow appears
Friday January 23 23:36 Io's shadow appears
Saturday January 24 00:03 Io begins transit
Saturday January 24 01:27 Europa's shadow appears
Saturday January 24 01:31 Callisto begins transit
Saturday January 24 01:54 Io's shadow disappears
Saturday January 24 02:07 Io ends transit
Saturday January 24 02:17 Europa begins transit
Saturday January 24 02:59 Callisto's shadow disappears
Saturday January 24 04:23 Europa's shadow disappears
Saturday January 24 04:54 Europa ends transit

(These timings are approximate, it is best to start observe a few minutes before the times indicated to be safe). Observers at other locations can adjust the time zone to determine the timings. If the sun is above the horizon at the specified time, you wont be able to see the transit.

See this article from Astronomy Now: "Jupiter’s moon dance and shadow play to delight observers:" http://astronomynow.com/2014/12/03/jupiters-moon-dance-and-shadow-play-to-delight-observers/

Thursday, January 1, 2015

Rosetta Update and Nature's 10 People who mattered this year.

Update to earlier blog post http://lowbrows.blogspot.com/2014/11/rosetta-spacecraft-expected-to-land-on.html ...

The magazine Nature published "365 days: Nature's 10, Ten People who mattered this year." The first of these 10 people was Andrea Accomazzo "A former test pilot steered the Rosetta mission to an icy world in deep space."

The Rosetta mission was the first successful attempt to place a lander on a comet. Some media reports described the mission as a failure. Any media reports of a "failure" completely miss the point.

After bouncing a few times, the lander was firmly on Comet Churyumov–Gerasimenko's surface, but in a position where its solar panels will not get any light. So the lander cannot operate as expected. Nevertheless the entire mission has been mostly successful, already resulting in new insights about comets.

The Rosetta spacecraft itself has operated fine, and the lander was able to collect data for a few hours on batteries before it shut itself off due to insufficient power. Mishaps like this happen, and don't necessarily turn a mission into a "failure." Besides there is still a real possibility that the lander will be able to get power over the next few months as the angle of the sun changes.

http://www.nature.com/news/365-days-nature-s-10-1.16562

Among other things the mission returned some beautiful photos. This picture is of the high cliffs on
Comet Churyumov–Gerasimenko taken by the Rosetta spacecraft

http://apod.nasa.gov/apod/ap141223.html