April 21 – May 3, 2015
“The Universe is gloriously transparent to visible light over journeys lasting billions of years. However, in the last few microseconds before light arrives at telescope mirrors on Earth it must travel through our turbulent atmosphere and the fine cosmic details become blurred. It is this same atmospheric turbulence that makes the stars appear to twinkle on a dark night… Putting a telescope in space is one way of evading this problem. As well as collecting visible light from its orbit high above the atmosphere, the Hubble Space Telescope also observes the infrared and ultraviolet wavelengths that are completely filtered out by the atmosphere.” From https://spacetelescope.org/about/
In 1610 the Italian scientist Galileo Galilei (1564-1642) viewed the glowing ribbon in the night sky, the Milky Way, through his telescope as individual stars. Before American astronomer Edwin Hubble (1889-1953) reported his discoveries from California’s Mt. Wilson Observatory in 1922-1923 the human conception of the universe was that the Milky Way galaxy was the entire universe, our star and its solar system a part of it. Hubble is known as “the man who discovered the cosmos,” having recognized a multitude of galaxies beyond the Milky Way. In 1946 Princeton astrophysicist Lyman Spitzer made a presentation to the RAND Corporation, “Astronomical Advantages of an Extra-Terrestrial Observatory.” Spitzer is credited with being the space telescope’s most important champion.
Launched aboard the space shuttle Discovery on April 24, 1990, the Hubble Space Telescope (HST), which is described as “the most successful and celebrated scientific instrument ever built,” was a collaboration between the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). The spirit of its builders is summed up by one of the team as working on “a common goal that everyone thinks is noble.” NASA is celebrating the 25th anniversary of Hubble from April 20 – 26.
The inspiring film, Saving Hubble, was an unannounced add-on to the Northeast Astronomy Forum (NEAF) the weekend of April 18-19. In the film, astronomers tell of aiming the Space Telescope at “the most boring spot in space” and leaving it positioned there for a time. The images that came back revealed “thousands, upon thousands, upon thousands of galaxies.” I was transported. In the film, Neil deGrasse Tyson says, “This one [HST] comes closest to being an extension of ourselves.” He is the Director of the American Museum of Natural History’s Hayden Planetarium. Hubble, the size of a school bus, orbits about 600 km (370 miles) above Earth!
The Lyrid meteor shower is predicted to be active through April 25, with peak shooting star activity, about 20 meteors per hour, late Wednesday night the 22nd and especially before dawn on Thursday the 23rd.
In the wonder of our place in the cosmos, remember Earth Day, April 22, and Earth Day Everyday. Pause to consider joining or renewing memberships in local, regional, national and international environmental organizations.
