Podcaster: Dr. Al Grauer
Title: Travelers in the Night Digest: Fresh Lunar Craters & The King
Organization: Travelers in The Night
Link : Travelers in the Night
Description: Today’s 2 topics:
- Some lunar craters are new. Bright flashes of light occur when one is created. If it happens in the dark part of the Moon it’s easily detectible from Earth. Dr. Mark Robinson of Arizona State Univ. used the LRO to find the new 62′ crater tied to the March 2013 flash of light.
- Jupiter has a huge effect on the solar system. It ejects comets out of the system and also occasionally sends them our way. In 1770 a comet came close to Jupiter and was hurled in our direction. It missed Earth but later went back near Jupiter and was ejected from the solar system altogether that time. It’s very possible that Earth wouldn’t even be here if not for Jupiter’s gravitational influence.
Bio: Dr. Al Grauer is currently an observing member of the Catalina Sky Survey Team at the University of Arizona. This group has discovered nearly half of the Earth approaching objects known to exist. He received a PhD in Physics in 1971 and has been an observational Astronomer for 43 years. He retired as a University Professor after 39 years of interacting with students. He has conducted research projects using telescopes in Arizona, Chile, Australia, Hawaii, Louisiana, and Georgia with funding from NSF and NASA.
He is noted as Co-discoverer of comet P/2010 TO20 Linear-Grauer, Discoverer of comet C/2009 U5 Grauer and has asteroid 18871 Grauer named for him.
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Transcript:
251 – Fresh Lunar Craters
Without an atmosphere and running water, craters formed on the Moon remain visible for eons. They are interesting targets for Earth bound observers with small telescopes to explore and photograph.
Not all of the Moon’s craters are old. Amateur and professional observatories routinely monitor the moon to detect some of the bright flashes which occur. Since 2006 the NASA Lunar Monitoring program has recorded more than 300 flashes created by meteor impacts on our Moon. The brightest so far was on March 17, 2013. Dr. Mark Robinson of Arizona State University headed up a team which analyzed recent data from the NASA Lunar Reconnaissance Orbiter. This team of researchers were able to spot the 62 foot diameter crater which was created by the impact that produced the March 2013 flash. They were also able to identify more than 200 lunar surface changes, out to almost 19 miles from the impact crater, which were caused by this event. This group of scientists were also able to verify that the impact of micrometeorites has modified the lunar soil to a depth of several feet or more.
Fresh craters on the Moon tell us about the number and the size distribution of objects which enter the Earth-Moon system. Current estimates suggest there are 24 craters larger than 60 feet in diameter which are produced on our Moon each year. Structures for lunar colonists and lunar experiments need to protect them from these as well the many many more BB sized or smaller objects which arrive at gun shot speeds from all directions in space.
252 – The King
The planet Jupiter is so bright that you can even spot it under the artificial light dome of one of our cities. Jupiter has a mass of more than 300 times that of the Earth and contains more than twice the mass of all of the other planets, dwarf planets, asteroids, and comets in our solar system combined.
Jupiter has had an enormous influence on the evolution of our solar system. It appears to have cleared out the inner solar system leaving enough rocky debris to form Mercury, Venus, Earth, and Mars. Without this action our solar system is likely to have turned out like the more than half of the planetary systems which we have found. These distant solar systems consist of non-inhabitable super Earth sized planets orbiting closely about their host stars.
In terms of the defense of planet Earth from impacting objects, Jupiter is a mixed blessing. It apparently deflects some of the long period comets out of Earth impacting orbits while sending some asteroids and comets our way. In 1770 a small comet came in from the outer solar system and passed near Jupiter. This encounter sent it straight towards Earth. Fortunately the King’s aim wasn’t perfect and this celestial visitor missed humanity by about a million miles. After two orbits of the Sun this comet once again passed near Jupiter. This time the King ejected it into interstellar space.
Look up where to find Jupiter on the internet and observe it. Jupiter is an awesome sight in binoculars or a small telescope. As you view this gas giant contemplate the fact that it is likely the reason you have a place to stand and air to breathe.
For Travelers in the Night this is Dr. Al Grauer.
End of podcast:
365 Days of Astronomy
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