What’s Up in the Sky – January, 2020
Important Work Being Done by Spacecraft
Lately I have found myself writing about things most readers will never see, mostly due to the weather, but timing, observing site availability and other commitments all affect our observing experience.
So my topic to kick off the new decade is a tale of two spacecraft – the Spitzer Space Telescope and the Parker Solar Probe. The former is near the end of its mission, the latter is just getting started.
First known as the Shuttle Infrared Telescope Facility (SIRTF), the Spitzer was born when NASA was seeking payloads for the Space Shuttle program. The telescope was one of four “Great Observatories” launched by NASA in the 90s and early 2000s that studied the universe in four different wavelengths of electromagnetic radiation. Spitzer observed infrared radiation, the Hubble Space Telescopes captures visible light, the Chandra X-ray and Compton Gamma Ray observatories’ names speak for themselves.
With the Spitzer Space Telescope we can not only look back in time but also observe invisible objects. Because of the expansion of the universe, light from distant galaxies is stretched to longer wavelengths (infrared) and that radiation took as many as ten billion years to reach us. So Spitzer is seeing things as they were ten billion years ago. Also, infrared radiation can penetrate our galaxy’s giant molecular clouds to enabling Spitzer to used to study stellar evolution.
But it’s the study of exoplanets in which Spitzer excels. Many exoplanets lie in orbits seen edge on alternately passing in front of and behind their star. The tiny dips in brightness as the planet passes directly in front of the star can be measured precisely by Spitzer. Some of the most important observations of distant planetary systems have been made in this manner.
After a remarkable 16-year exploration of the infrared universe, Spitzer will be retired on January 30.
The flip side of that coin is the Parker Solar Probe, a spacecraft currently in an orbit around the Sun that stretches out to Venus. With the primary goal of studying the Sun’s corona and solar wind, the spacecraft will dip as close as 4 million miles from the “surface”. This will enable it to study the speed of the solar wind and the birthplace of the highest-energy solar particles.
Parker Solar Probe will make 24 orbits of the Sun including 7 close encounters with Venus for “gravity assists”. The entire mission will last almost seven years. The mission is critical in that it will increase our understanding of the interaction between the solar wind and the Sun’s corona. This, hopefully, will lead to a clearer picture of the causes of the coronal mass ejections or “solar storms” that can disrupt electronics and power transmission.
So, although not objects for astronomical observations, these satellites are just two of the spacecraft doing important work up in the sky.
This month in history:
Jan. 1: Isaac Azimov born – 1920
Jan. 4: NASA cancels further production of Saturn V rockets – 1970
Jan. 13: First women astronauts selected by NASA – 1978
Jan. 19: New Horizons spacecraft launched on it’s journey to Pluto – 2006
Jan. 27: Apollo 1 astronauts Chaffee, White and Grissom die in fire in capsule-1967
Jan. 28: Seven astronauts killed when Space Shuttle Challenger explodes during launch – 1986
