A week ago I posted on  Death by a Gamma Ray Burst?   This week, I focus on another space invader, a large asteroid.  PBS has had several documentaries on this topic:   The Asteroid and the Dinosaur  and   Dinosaur Apocalypse . The scientific term for the above is  Impact Event .  The biggest Earth event might have been the  Big Splash , or the Theia Impact: This when our Moon was formed approximately 4.5 billion years ago. Theia, the mythical Greek Titan, was the colliding body, mother of Selene, the goddess of the Moon. The isotope ratios of lunar and terrestrial rock are identical. There are many theories, but one is that the Moon was formed by the tangential impact upon Earth of a body the size of Mars. Much of this giant-impact consensus emerged from a 1969 conference held at Kona, Hawaii.  Those who don't believe are called the agnostics. But our solar system is today quite different, and planet-sized impact neighbors are no longer present. 2 billion years ago an asteroid cal

Before I go into my Wednesday science topic, one note about COVID-19.  Of course, with so many tests now taken at home and not reported, surely the 100,000 or so new cases/day in the U.S. must be higher.   Here is one estimate by the University Columbia's Jeffrey Shaman : Shaman's research group turned to using models to estimate the "ascertainment rate" — the portion of real infections that were being captured in official case counts. That rate has fluctuated — at the end of 2020, they estimated one in four cases were being counted. During the omicron surge it was closer to one in six.   Now with the widespread availability of at-home rapid tests that aren't reported to health departments, Shaman thinks the true number of cases may be in the ballpark of eight times higher than case counts. In other words, instead of 100,000 new cases a day, the true number may be 800,000 cases per day. As terrible as that may sound, I think there is a silver lining.   So many hav

                                         From  Worldometer  (new  COVID-19 deaths yesterday):          DAY    USA    WORLD     Brazil      India      South Africa June     9    1093     4732         1185        246       82 July    22     1205     7128         1293      1120     572 Aug    12     1504     6556        1242        835     130 Sept     9     1208      6222       1136       1168       82 Oct     21     1225      6849         571        703       85 Nov    25      2304    12025        620        518      118 Dec     30      3880    14748       1224       299      465 Jan      14       4142     15512        1151        189      712                  Feb      3       4005    14265       1209       107      398 Mar     2        1989      9490        1726       110      194 April   6          906     11787         4211       631       37 May    4         853     13667         3025     3786      59   June   1         287    10637         2346      3205       95  July   7