Category Archives: Astronomy

Near Miss By Asteroid On 19 April 2017


Reposting a Dr Roy Spencer’s  posting about  a large Asteriod that will pass close to the Earth on April 19  2017.

Half-mile Wide Asteroid Close Approach on Wednesday

April 18th, 2017

An asteroid capable of destroying Washington D.C. and New York City at the same time will be making its closest approach to Earth on April 19.

At a half-mile wide, it will have over 30,000 times as much mass as the 2013 meteor which exploded over Russia in 2013.

The current asteroid, called “2014 JO25“, is traveling at the unimaginably fast speed of 75,000 mph. It has been estimated that an asteroid of this size is capable of wiping out an area the size of New England, and causing global cooling from the dust that would be lofted into the stratosphere. “2014 JO25” will be the closest appoach asteroid of this size in the last 13 years.

Good News, Bad News

The good news is that even at closest approach, the asteroid — about the size of the Rock of Gibraltar — will safely pass by about 4.6 times as far away from Earth as the moon.

The bad news is that this asteroid was only discovered in 2014, and even if it was on a collision course with Earth, there probably would not have been enough time to mount a mission to hit it with a nuclear-weapon tipped rocket. This is why NASA has been surveying the skies, discovering new asteroids on a routine basis. While most of these are small, the relatively recent discovery of Wednesday’s asteroid suggests we will not have much time to respond if we discover one on a collision course with Earth. I suspect we will eventually have a rocket designed and ready for an intercept, just in case.

 

Scary

cbdakota

Solar Cycle 24 And Solar Wind Storm


Solar Cycle 24 activity, using Sunspots as the proxy, is slowing down considerably. The International number for March was 38.4. The smoothed International Sunspot number is estimated at 56.1. The March number will not be official for another 6 months. The chart below, the black line, labeled Ri is the International number which is the sum of the Rnorth (red) and Rsouth (green) Sunspot numbers.

march15cycle24

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Solar Cycle 24—Ending February At Low Activity


Solar Cycle 24 activity is relatively low as the month of February comes to a close. On February 27, only three visible Sunspot clusters could be seen. Solar Cycle 24 International Sunspot smoothed number for February 2015 looks like it will be about 65.

regions_feb27

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What Did The Hubble Telescope Find In 2003?


hubble telescopeimagesThe Hubble telescope photographed the most distant objects ever, some 13 billion light years away during a 4 month period in 2003.  This is old news and some of you know about this event.  But even so it is worth seeing it again.   Click here to see the show.

 

cbdakota

Climate Cycles-Part 2 Earth’s Obital Cycles Control Glacial Periods


There are several theories for the cause of glacial periods–Cycles of glaciers followed by  interglacial warm periods and then repeating that cycle. Of those theories, the Milankovitch Cycles theory seems to have a broad base of adherents who believe it to have the best answer that question.   The Milankovitch theory has some weaknesses.  So this posting remains skeptical, however, it appears that there are good reasons why it is probably the most accepted theory.  That Richard Lindzen is a supporter of the theory is one of the good reasons.

The Milankovitch theory says that moving in and out of glacial periods is a result of variation in the Earth’s orbit and orientation.  Three parameters—Earth’s eccentric orbit around the Sun, the planet’s axial tilt and the procession of its axis are the basis of the theory.   These parameters are pretty well defined.   The coincidence with certain combinations of the three parameters and the paleohistory of glacial periods is reasonably close.   A posting by Doug Hoffman on his blog, the Resilient Earth “Confirmed! Orbital Cycles Control Ice Ages” is very good.  I could not say it as well, so this posting  will lift much from his.  

 

From Hoffman’s posting:

Earth’s orbit goes from measurably elliptical to nearly circular in a cycle that takes around 100,000 years. Presently, Earth is in a period of low eccentricity, about 3%. This causes a seasonal change in solar energy of 7%. The difference between summer and winter is a 7% difference in the energy a hemisphere receives from the Sun. When Earth’s orbital eccentricity is at its peak (~9%), seasonal variation reaches 20-30%. Additionally, a more eccentric orbit will change the length of seasons in each hemisphere by changing the length of time between the vernal and autumnal equinoxes. (Click on the Chart to enlarge.)

relisearthEccentricity_Obliquity_Precession-noaa_dlh-500

Variation in Axial Obliquity, Orbital Eccentricity, and Polar Precession.NOAA.

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Asteroid DA14 Passes By Earth Friday 15 Feb.


NASA provides the video animation of asteroid DA14 that passes  near-by the Earth on Friday 15 February 2013.  The asteroid will be about 17,150 miles (27,600 kilometers) above Earth’s surface.

http://www.nasa.gov/multimedia/videogallery/index.html?media_id=159813511

cbdakota

Asteroids Caused By Global Warming?


Just when you thought it might be safe, along comes another  misinformed media talking head.  This one thinks that even asteroids could be caused by global warming.  My guess is that she is not alone in being this deep into the Koolaid.  She does not seem to think for herself; she just believes everything the alarmist preach.

Read this and be sure to look at the video.

cbdakota