Wednesday, January 28, 2015

Barns Are Painted Red Because of the Physics of Dying Stars

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:"

Thursday, January 1, 2015

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

Update to earlier blog post ...

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.

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

Wednesday, December 24, 2014

Curiosity Detects Methane Spike on Mars

Last week the following was posted by NASA....
Dec. 16, 2014: NASA's Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory’s drill.
"This temporary increase in methane -- sharply up and then back down -- tells us there must be some relatively localized source," said Sushil Atreya of the University of Michigan, Ann Arbor, and Curiosity rover science team. "There are many possible sources, biological or non-biological, such as interaction of water and rock."
Traces of Methane have been seen on Mars in the past. While it is possible that this Methane and the other organic molecules are indications of the presence of bacteria on or near the surface of Mars, there are non-biological explanations as well. Scientists are continually analyzing data in an attempt to determine the source of this Methane. For the full NASA post go to....

Also see this post from the University of Michigan....

Saturday, December 6, 2014

Analysis of Higg's Boson Decay Now Shows no Suggestion of Additional Particles (Still no particles that explain dark matter).

Update on the blog post of Friday, January 11, 2013

Shortly after the discovery of the Higgs Boson two years ago, physicists suspected that a new particle lurked in the data (new particles such as this could lead to an explanation for dark matter).

The Higgs Boson is unstable and rapidly decays into other particles. It does so through several different "channels", one  is the gamma gamma channel where the Higgs Boson decays into two gamma particles. This decay cannot occur in one step, it must occur through intermediate particles. The percentage of decays that goes through each decay is called the yield. The yield in turn is based on the available particles. If there are unknown particles available, this will affect the yield.

There was an anomoly in the yield of the gamma gamma channel (the yield was higher than expected) which suggested the existance of a previously undiscovered particle or particles. Such particles might be the components of dark matter.

However based on more careful analysis, this anomoly has disappeared and now there is no suggestion of additional particles.

That doesn't rule out future experiments finding new particles. The LHC (Large Hadron Collider) where the Higgs Boson was discovered is currently undergoing renovations. It will restart at higher energy in 2015. When it restarts, it will be looking for new particles as well as exploring the properties of existing particles, especially the Higgs Boson.

For more information see: (to read the entire article requires a subscription to Science News).

Wednesday, November 26, 2014

Gravitational Wave Discovery Looks Doubtful In New Analysis

Update on the blog post of Wednesday, March 19, 2014 (

In March gravitational waves were discovered from the early universe (moments after the big bang). This discovery is now in doubt. New analysis suggests that dust within our own galaxy is responsible for much if not all of the signal. While it doesn't completely rule out the presence of gravitational waves, it is a significant setback.

For more information see:

Tuesday, November 11, 2014

Rosetta spacecraft expected to land on Comet 67P/Churyumov–Gerasimenko

This Wednesday Morning (November 12) at 10:30AM Eastern Standard Time the Rosetta spacecraft is expected to land on Comet 67P/Churyumov–Gerasimenko. If successful, this will be the first time any spacecraft has landed on a comet.

See these links for more information...

To watch the landing on streaming video, go to either of these sites (note there is a 30 minute delay, if the landing occurs at 10:30AM, we will see the landing at 11:00AM).,2817,2471982,00.asp