July 1 2015 Astronomy Newsletter
Here's the latest article from the Astronomy site at BellaOnline.com.
APOLOGY to Gmail (& maybe other) Readers: This newsletter looks OK in Yahoo, but for some reason Gmail is showing it with lots of HTML markers. They aren't in my original document, and I don't see them on my newsletter send page, so I can't get rid of them. I can only say "sorry" and hope that other readers aren't similarly affected.
Smallest Star in the Universe
No one could possibly say that a star is the smallest one in the whole Universe. But the smallest known star is 2MASS J05233822-1403022, which is a pretty big name for a star that's about the size of Saturn. Could there be even smaller ones as yet unknown?
On June 30, the 107th anniversary of the Tunguska Event, the first Asteroid Day was introduced to make public and governments more aware of the serious threat of an asteroid hitting the Earth.
Did you know . . . that between 2000 and 2013, a network of sensors that monitors Earth listening for the signature of nuclear detonations detected 26 explosions on Earth ranging in energy from 1-600 kilotons -- all caused not by nuclear explosions, but by asteroid impacts.
Here is a short video about about Asteroid Impacts: https://www.pinterest.com/astrobella/asteroids-and-meteors/
I'm afraid that Asteroid Day caught me unawares, so the events on this website happened yesterday: http://www.asteroidday.org/ However it has a lot of interesting and useful information on it.
*Happy birthday, Henrietta Leavitt*
Henrietta Swan Leavitt was born on July 4, 1868.
Henrietta Leavitt isn't a well known name, but a century ago she made one of the most important discoveries of 20th century astronomy. Previously, astronomers could only measure distances up to 100 light years, but her work extended that to 10 million light years.
Find out more about about this remarkable woman who made three major contributions to astronomy: http://www.bellaonline.com/articles/art29166.asp
*Happy birthday, USA*
Happy 4th of July to American readers. Have a great holiday. And what about a Cosmic 4th of July?
What links the USA's Independence Day holiday, the Crab Nebula and NASA's Deep Impact spacecraft? What links the American War of Independence with the planet Uranus? And what is the Fireworks Galaxy? Here's the story. http://www.bellaonline.com/articles/art180958.asp
*The longest day*
No, this isn't about the summer solstice, it's about June 30 actually being longer than other days. Only by 1 second, so if you felt the day was dragging on, it must have been for other reasons.
You know that we have leap years to keep the calendar in synch with the seasons, since Earth's trip around the Sun doesn't take an even number of days. Well, the day is based on the Earth's rotation - and that keeps getting slower. But although it doesn't get slower very fast, these days making precision astronomical measurements needs precision timing. So every now and then, we get a leap second.
Please visit http://astronomy.bellaonline.com/Site.asp for even more great content about Astronomy.
I hope to hear from you sometime soon, either in the forum http://forums.bellaonline.com/ubbthreads.php/forums/323/1/Astronomy or in response to this email message. I welcome your feedback!
Do pass this message along to family and friends who might also be interested. Remember it's free and without obligation.
I wish you clear skies.
Mona Evans, Astronomy Editor
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