A Near Miss at Mars

Near MissThis graphic shows the predicted orbit of comet C/2013 A1 Siding Spring as it swings around the inner Solar System in 2014. On 19 October, the comet will pass very close to Mars. Its nucleus will miss Mars by about 132,000 km. As it flies by it, will be shedding material moving at over 50 km/s, relative to Mars and Mars-orbiting spacecraft. Even a tiny particle only 0.5 mm across moving at that speed could cause significant damage to a spacecraft.

NASA currently operates two Mars orbiters, and a third on its way, arriving in Martian orbit a month before the comet flyby. Teams operating those orbiters plan to adjust their orbits so that the spacecraft will be on the opposite side of the Mars when the comet is most likely to pass by.

Image Credit: NASA

Merope Nebula

Pleiades_Spitzer_MeropeThe Merope Nebula (aka NGC 1435) is a diffuse reflection nebula in the Pleiades star cluster, surrounding the 4th magnitude star Merope. It appears to be about the size of the full moon. It is illuminated entirely by the star Merope which is embedded in the nebula. The nebula appears blue in visible light photographs because of the fine carbon dust spread throughout the cloud. This false color view was put together using infrared data from the Spitzer Space Telescope.

Image Credit: NASA

The Perseus Dark Matter Matter

Video Credit: NASA

Personal Note—I contributed to the design of the cryogenic temperature control system being used to cool the detector array in the Soft X-ray Spectrometer that will fly on Astro-H. The system is capable of holding the detector array at 0.05° above absolute zero with a stability better than ±0.000001°.

When an individual x-ray photon strikes one of the pixels in the SXS detector, the energy raises its temperature slightly which changes the resistance of the cell—the more energetic the photon, the greater the change. The low operating temperature and the tight regulation are necessary to make lower energy x-rays detectable and reduce system noise.


The Earth’s magnetic field which shields the planet from severe space weather often develops holes that allow the largest leaks of solar particles. This short animation shows what can happen based on findings from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission.

Video Credit: NASA

Too Close for Comfort

Video Credit: NASA

UPDATE—A personal note: I contributed to the design of components of the Burst Alert Telescope instrument on Swift. My contributions include the ultra-quiet power regulators for the detectors in the instrument, the variable high-voltage supply for the detectors, and the pulse-width-modulation regulator for the thermal control system of the BAT. The same PWM regulator was also used in other locations on the satellite.

NGC 1433

Composite_NGC_1433This detailed view shows the central parts of the nearby active galaxy NGC 1433. The dim blue background image, showing the central dust lanes of this galaxy, comes from the Hubble Space Telescope. The other colored structures near the middle of the image are from ALMA observations. ALMA is the Atacama Large Millimeter/sub-millimeter Array, an astronomical interferometer of radio telescopes in the Atacama desert of northern Chile.

Image Credit: ESO / NASA / ESA


One of my hobbies is amateur radio, and one of the things that many of us ham radio geeks keep an eye on is sunspots. Sunspots are darker, cooler regions on the Sun created by intense magnetic fields breaking through the surface. As that solar activity increases, the Sun’s effect on the Earth’s ionosphere generally improves the propagation of shortwave radio signals. The Sun showed a substantial increase in sunspots over the first part of this month. This movie and still (assembled from data taken by the Solar Dynamics Observatory) show the Sun in filtered white light. It’s dotted with more and larger sunspots than we have seen for quite a while, and I’ve noticed improved radio propagation, occasionally extending to VHF bands. The Sun is supposed to have passed the peak for this 11-year sunspot cycle, but it will still be producing more sunspots and solar storms during the rest of this solar cycle.

Video Credit: NASA


KBOsThese two multiple-exposure images from the Hubble Space Telescope show Kuiper Belt objects or (KBOs) moving against a background of stars in the constellation Sagittarius. The two KBOs are roughly 4 billion miles from Earth. The Kuiper belt is a debris field of icy bodies left over from the solar system’s formation 4.6 billion years ago.

Hubble has been given the go-ahead to conduct an intensive search for a suitable outer solar system object that the New Horizons spacecraft could visit after the probe streaks though the Pluto system in July 2015.

Image Credit: NASA

Mintaka, Alnilam, and Alnitak

orion_arisingThose are the names of the stars in Orion’s belt, and they can be seen peeking through Earth’s atmosphere in this picture made from the International Space Station by astronaut Reid Wiseman. Orion’s sword, home to the great Orion Nebula, hangs above his belt in an orientation opposite to what those of us who live in the northern hemisphere are used to. Rigel, at the foot of Orion, is still higher above Orion’s belt. Sirius, alpha star of the constellation Canis Major, is to the right of center in the frame. That’s the station’s Destiny Laboratory module is in the foreground at the top right.

Image Credit: NASA