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Bakersfield Night Sky - September 6, 2020
By Nick Strobel

Mars is now getting better positioned for evening observations of its enlarging disk as Earth catches up to for a . As we get closer, more detail is visible in our telescopes. Hopefully, the sky is clear of all the smoke from the fires. Mars becomes first visible at around 9:30 PM on the eastern edge of the dim constellation Pisces (see the star chart below). Almost straight above Mars and Pisces will be the Great Square of Pegasus. To the left of Pegasus is Andromeda with the closest large galaxy to us, the , just above the middle stars of Andromeda.

A team of astronomers using the ultraviolet-observing capabilities of the Hubble Space Telescope has . The halo of gas is made of outflows from supernovae as well as inflowing gas that will later be made into stars and planets. The extent of the halo is enormous. If we could see it in the visible band with our eyes, it would be about three times the width of the Big Dipper on our night sky. Our home galaxy, the Milky Way also has a huge halo of rarified plasma that is probably the same size, so our two plasma halos are already bumping into each other.

Now the plasma halo does not glow in the ultraviolet. Astronomers used the ultraviolet spectrometer on Hubble to look at ultraviolet light from , passing through the plasma halo. As the light passes, some of it gets absorbed by the plasma halo. With enough quasars (43 in this study) positioned on the sky around the Andromeda Galaxy, the astronomers were able to see how the absorption changes in different regions around the Andromeda Galaxy. These observations have to be done in space because . That's a good thing, by the way. If all of the ultraviolet light from space reached the ground, life on the surface would be impossible.

A is to the left of Mars tonight. By the time Mars is high enough to see easily in the east, the two giant planets, Jupiter and Saturn in Sagittarius will be in the south-southwest. When the smoke was thick in our sky only Jupiter was bright enough to pierce through but on the last couple of night walks around the perimeter of our neighborhood, we've been able to see the three stars of the Summer Triangle: high overhead in Lyra, at the tail of Cygnus, and at the neck of Aquila. We can also make out most of the other stars of Cygnus, including the ones that make up the Northern Cross, and several of Aquila's other stars.

One astronomy research story that made a bit of a was the one about from (yes, I'm a tiny bit proud of that pun). It has been long thought that because Earth formed so close to the sun that all of the water in the surrounding nebula would have remained as vapor and never could have condensed to eventually form our oceans and rivers. Therefore, the water would have had to come from comets and/or asteroids that formed farther from the sun and were drawn in later to the inner solar system by the sun's gravity.

To check that out astronomers have used ratios of such as hydrogen, oxygen, calcium, and some metals to see if the water and rocky compositions of the asteroids and comets match what we have here on Earth. Well, sorta sometimes but not well enough to explain all the water we do have. An example of an isotope signature is . Heavy water has the same chemistry as regular water but one or both of the hydrogen atoms in the H2O molecule have an extra neutron in their nucleus. That makes the nucleus of the hydrogen atom more massive 鈥斺�渉eavier鈥�, so water with the extra neutron(s) is 鈥渉eavy water鈥�.

. Some of the chips of asteroids that fall to Earth鈥攎eteorites鈥攈ave water ratios that are close to Earth's ratio but isotope ratios for other elements are off. Isotope ratios are such a powerful chemical tool to tell where something comes from.

found that a group of meteorites called enstatite chondrites which fits all the isotopic signatures of Earth and the moon, have a , especially the oldest most pristine ones of the set, to conclude that Earth's water formed with the rest of the Earth. That matches earlier showing that the water in the forming inner planets would not have all dissipated away.

Stay healthy, wear a mask and keep six feet between you and others in crowds to prevent passing on COVID19 to others. Only you can prevent infections.

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Director of the William M Thomas Planetarium at 太阳城官网
Author of the award-winning website