February 18, 2024

By Nick Strobel | 02/14/24
Late February at 8:30 PM looking southeast

The spring flowers in my yard have already been blooming as the daylight steadily increases and temperatures warm. The constellation Leo has now gotten up high enough in the evening for me to point it out to people attending shows at the William M Thomas Planetarium during the tour of the evening sky we do in every show. The appearance of Leo rising in the east in the evening tells us that spring is coming soon. Because my yard is prettiest in early spring with all of the daffodils, poppies, African daisies, cyclamen, calendulas, and scarlet flax blooming, I look forward to this time of year!

At sunset, Jupiter is the bright “star” high in the south-southwest. When the sky darkens and the rest of the stars come out, you’ll see that it is below the stars of Aries and close to the head of Cetus. To the east of Jupiter is the winter constellation set centered on Orion with Taurus to the upper right of Orion, Auriga (sporting bright Capella) above Orion, Gemini to the upper left of Orion, Canis Minor to the left of Orion, Canis Major (showing off super-bright Sirius) to the lower left of Orion, and Lepus below Orion.

Tonight a waxing gibbous moon will be just above the horns of Taurus as it heads for Gemini. On Wednesday, February 21, the moon will be above the Beehive Cluster at the heart of Cancer. The bright moon will probably wash out the cluster, so you’ll need binoculars to pick it out. When the moon is not nearby, then the Beehive can be seen as a fuzzy patch without binoculars. On Friday, February 23, the full moon will be next to Regulus at the chest of Leo. The Sickle part of Leo is the head and front of Leo.

NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission launched successfully ten days ago. PACE’s instruments will measure the large, macroscopic impact of microscopic things: the tiny phytoplankton in our oceans and the tiny aerosol particles in our atmosphere. PACE’s instruments can observe in ultraviolet, visible, and near-infrared light to track the distribution of phytoplankton across the globe. Phytoplankton play a key role in Earth’s carbon cycle by absorbing carbon dioxide from the atmosphere to begin the process of storing it in cells at the foundation of the food chain in the oceans. Tracking the phytoplankton will also help us forecast the health of fisheries, track harmful algal blooms, and identify other changes in the marine environment.

Two polarimeter instruments on PACE will detect how sunlight interacts with aerosol particles in the atmosphere (sea salt, smoke, human-made pollutants, and dust), giving us new information (size, composition, abundance, etc.) on atmospheric aerosols and cloud properties, filling in the largest gap in our understanding of Earth’s climate system. The various effects of aerosols for cooling (reflecting sunlight) and heating (absorbing sunlight) have been the largest uncertainty in our computer simulations of Earth’s climate. Aerosols also affect cloud formation and properties. Clouds of ice crystals have different climate effects than clouds of water droplets. Earth’s climate system has a number of interconnected parts with effects that propagate through the system in complex ways, including various feedback loops. Some parts of the system we’ve understood very well for over a century but other parts such as aerosols have been less understood, especially on a global scale. PACE is finally going to give us the high-resolution spatial and temporal data we need for the roles that aerosols in the air and phytoplankton in the oceans play in making present-day Earth such a nice place for human civilization to thrive. For more about PACE, please visit the PACE Mission web page.

A set of gorgeous pictures of 19 nearby spiral galaxies taken with the James Webb Space Telescope was recently published. Because Webb is an infrared telescope, the images showed all the intricate details of the dust clouds in the interstellar medium and star formation regions. Although these galaxies have been imaged in the infrared by other telescopes, Webb’s superior resolution means we can now see so much more exquisite detail than before. In the spiral galaxy NGC 628, astronomer Elizabeth Watkins was able to count over 1700 bubbles that had been carved out in the interstellar medium by exploding stars. Matching these images with others taken by the Hubble Space Telescope in ultraviolet and visible, the Very Large Telescope in Chile, and in microwaves with the ALMA observatory also in Chile, will help us understand all of the details of star formation to star death (as well as provide beautiful images for computer desktop backdrops). Oh… the name of this study is Physics of High Angular resolution in Nearby GalaxieS—PHANGS. I wonder how many glasses of beer it took to come up with that acronym.

Nick Strobel

Director of the William M Thomas Planetarium at Bakersfield College

Author of the award-winning website www.astronomynotes.com