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Pictured is a Delta IV rocket launch from Cape Canaveral on November 21st, 2010. The image is a 20 second exposure taken at dusk, shot from about 100 miles west of the launch site. The launch placed a classified payload in orbit for the United States Air Force.
Difficult but not impossible to catch against the dawn or dusk sky, spotting an extreme crescent moon can be a challenge. The slender crescent pictured was shot 30 minutes before sunrise when the Moon was less than 20 hours away from New.� A true feat of visual athletics to catch, a good pair of binoculars or a well aimed wide field telescopic view can help with the hunt.
The Sun is our nearest star, and goes through an 11-year cycle of activity. This image was taken via a properly filtered telescope, and shows the Sun as it appeared during its last maximum peak in 2003. This was during solar cycle #23, a period during which the Sun hurled several large flares Earthward. The next solar cycle is due to peak around 2013-14.
Located in the belt of the constellation Orion, Messier 42, also known as the Orion Nebula is one of the finest deep sky objects in the northern hemisphere sky. Just visible as a faint smudge to the naked eye on a clear dark night, the Orion Nebula is a sure star party favorite, as it shows tendrils of gas contrasted with bright stars. M42 is a large stellar nursery, a star forming region about 1,000 light years distant.
Orbiting the planet in Low Earth Orbit (LEO) every 90 minutes, many people fail to realize that you can see the International Space Station (ISS) from most of the planet on a near-weekly basis. In fact, the ISS has been known to make up to four visible passes over the same location in one night. The image pictured is from the Fourth of July, 2011 and is a 20 second exposure of a bright ISS pass.
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Next to the Sun, the two brightest objects in the sky are the Moon and the planet Venus. In fact, when Venus is favorably placed next to the Moon, it might just be possible to spot the two in the daytime. Another intriguing effect known as earthshine or ashen light is also seen in the image on the night side of the Moon; this is caused by sunlight reflected back off of the Earth towards our only satellite.
A mosaic of three images taken during the total lunar eclipse of December 21st, 2010. The eclipse occurred the same day as the winter solstice. The curve and size of the Earth�s shadow is apparent in the image.
Review: How Old is the Universe? By David A. Weintraub.
Probably the toughest questions an astronomer ever has to field with the public are those in cosmology. How old/how big/how far are truly mind bending questions, and difficult to explain to the average man on the street in sound-bite style. This week, we look at David Weintraub�s latest, How Old is the Universe? out by Princeton Press. Fans of this site will remember our review of Is Pluto a Planet? also by Mr. Weintraub a few years back.
How Old is the Universe? Serves as an address on the state of cosmology today, and how we�ve accumulated our knowledge up to this point and what it says about our present and future. Its premise is a simple one; a basic question of the age of existence and the ramifications that it implies. A field such as cosmology builds on evidence-based suppositions; the author starts with how we know the age of the Earth, Moon and bodies in the solar system and how this puts rough constraints on the lower age limit of the cosmos. You can�t be older than your parents by definition, and objects in the universe cannot be older than the universe itself.
Cosmology has rapidly moved in the last century from the realm of philosophy to one of science. Imagine; the universe of our grandparents consisted of the Milky Way, with a few dim smudges on a photographic plate that defied description. Edwin Hubble blew the doors off of that in the 1920�s, showing that our galaxy is but one in the cosmos. And our great-grandparents had the formidable task of measuring the stellar parallax, using nothing but windup time pieces and wire transit micrometers and a sharp eye� the road to modern cosmology has been a tough one indeed.
Universe climaxes with another quiet watershed moment of the 20th century; the discovery of the Cosmic Microwave Background radiation (CMB) by Penzias & Wilson�in 1964. Here is science at its best; a surreptitious discovery of a prediction made by theory.
The author also covers other points of evidence that builds a compelling case for the Big Bang; did you know that the ages of globular clusters fit nicely with the constraints of predictions, or that the temperature/luminosity of white dwarfs suggests a lower limit to the age of the universe? Or that the Hubble constant has been narrowed down considerably in the past few years, or that the ratios of lithium, deuterium and even the very existence of such elements as boron suggest that the Big Bang had to occur and the the resulting universe was non-homogeous? Universe covers all of this and more, looking at the compelling questions of modern cosmology; is the universe open, flat or curved? What is dark energy? Where is a majority of the universe (aka dark matter) hiding? These are questions we may just see answers to in our lifetimes.
Read How Old is the Universe? To get a compelling look at a fundamental question. The cosmological questions are always the toughest to answer, as our knowledge stacks one careful cornerstone after another. It seems that after evolution and climate change, the Big Bang Theory stacks up as public enemy no. 3 in the theories that the anti-science crowd wants to knock down. It�s strange that this should be so; most creation tales start with a finite beginning, a �let there be light� moment that jibes well with what modern cosmology tells us, if you allow for a modicum of allegory� in our minds, a steady state universe would be more bizarre. Read Mr. Weintraub�s work to arm yourself with the best reply, that of knowledge and wonder at the universe we all inhabit.