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Once full darkness sets in, the view of Virgo in the east is one that brings many galaxies into the sky. With a decent small telescope and a dark viewing site the intentional star gazer can enjoy exploring the second-largest constellation recognized by official astronomical folks. Filled with a collection of several thousand galaxies located 60 million light years away, the Virgo Cluster can provide hours of exploration to a dedicated astronomy aficionado.
The Virgo Cluster is the largest structure in our part of the universe. They are bound together by their gravitational pulls and so they move together through the vastness of space. The collective pull is so powerful it even exerts a strong pull on the Milky Way and the local group of galaxies to which it, and our solar system, belong.
The largest member of the cluster is one of the Messier Objects, M87. It is a giant elliptical galaxy whose nucleus is a giant black hole — the first one ever directly imaged — millions of light years across and contains at least a trillion stars. By contrast, our Milky Way Galaxy is a hundred thousand light-years across and possibly contains a hundred billion stars. In case you are intrigued by black holes, the core of M87 is a black hole that is 6.6 billion times the mass of the sun and is the most powerful known source of radio energy among the thousands of galactic systems constituting the so-called Virgo Cluster.
The beautiful blue star Spica (SPY-kuh) that marks the sheaf of wheat Virgo is holding, or the diamond of her engagement ring as some of us like to call it, is a double star system, but the pair is so close together, only a million miles separate them, they appear to be only one star. Spica is the 16th brightest star in our sky and one that is sure to bring recognition if you look for it after sunset in the east.
Late night sky watchers can enjoy the rising of Scorpius with the red supergiant star Antares, anti-Aries, the rival of Mars, emerging from the horizon in the east to slowly wend its way into the sky, bringing with it just before dawn the constellation Sagittarius, Pisces, and the Great Square of Pegasus.
The planets visible in the predawn sky remain the same one for a long time. Venus, Jupiter, Saturn, and Mars’ orbits interacting with Earth’s revolution and rotation are the reasons we see different planets at different times and for the length of time they remain visible either as morning or evening spectacles. Since Venus’ orbit is within the orbit of Earth, we see it change more frequently. The blaze of the sunlight reflecting off the poisonous atmosphere of Venus makes it the brightest planet in the sky from our point of view.
Monday is the new moon phase, which means our natural satellite is hidden in the glare of the sun’s light. Since our planet is tilted at a 23.5 degree angle, we do not have a lunar or solar eclipse each month. Geometry is funny that way. There are several sites on the internet that have good illustrations about the reason why if you care to learn more. Here is one suggestion: https://moon.nasa.gov/resources/435/why-dont-we-have-a-solar-eclipse-every-month/
You might enjoy creating a story to explain why this is so. Many ancient cultures shared stories about sky marvels to explain the “why” to their children. Stories may create a special bond among your own family when the big question is “why” around the dinner table.
Until next time, KLU.
