The Celestial Sphere

by Matthew Johnson

Viewers on NASA’s Jet Propulsion Laboratory website on February 18 witnessed telemetry history—the Mars rover, Perseverance, ferrying its small helicopter companion, Ingenuity, entered Mars’s thin atmosphere at 52 kilometers per second, slowed its descent with retro-thrusters and, after deploying a parachute, touched down in the Jezero crater landing site. Immediately after this miraculous and safe landing, the rover began transmitting back to Earth photographs of a dusty Martian rock-strewn desert landscape!

Perseverance’s mission is to seek clues as to whether life ever existed on Mars. It will also study the evolution of Mars’s climate, its surface and the interior of the planet. The rover will test technologies for future human exploration of Mars. In addition, Perseverance will collect and cache samples of material for a possible future return to Earth. An exciting time.

There are no significant meteor showers this month and other than the gorgeous winter constellations, Mars is the only planet that continues to highlight the night sky. On March 4, looking high overhead, deep into the south-southwest one hour after sunset, Mars will offer a nice apparition, easy to discern, with the Pleiades just to its right. On the night of March 19, Mars joins the moon and the red giant star Aldebran again high overhead in the constellation Taurus. Mars is slightly lower and to the right of the moon, with Aldebran slightly to the left and below the moon.

In previous articles, Mars has frequently been mentioned as being a brilliant planet, presently easy to observe. This is because its orbit has brought it in close proximity to Earth, fortuitous for the best naked-eye observation in years. This proximity is also why the spacecraft Perseverance was launched some 600 days ago—not before or after. 

During March, almost all naked-eye observation of the planets must take place during the early morning hour just before dawn. On March 1, Mercury, Saturn and Jupiter can be found in a line along the east-southeast horizon about 30 minutes before sunrise. Four days later, a wonderful Jupiter conjunction will take place. Again, looking east-southeast, the planet Mercury will move directly in front of Jupiter, providing the most brilliant light in the heavens. This is a must see. However, it will be a difficult event to catch without a clear skyline, as the Mercury/Jupiter conjunction occurs just above the horizon. Venus is behind the sun for a few months, meaning no viewing this planet until later in the spring.

Daylight Saving Time begins March 14 at 2 a.m., so set those vintage and antique clocks and watches forward one hour.

The long-awaited vernal equinox occurs on March 21. On the equinox (from the Latin for “equal”), daylight and nighttime are both roughly 12 hours long and it signifies the first day of spring.

Moon Phases:

March 5: Last quarter (left half of the moon illuminated).

March 13: New moon (no visible moon). The best time of the month to observe faint objects such as distant galaxies and star clusters is during the few days before and after the new moon, when there is no moonlight to interfere.

March 21: First quarter (right half of moon illuminated).

March 28: Full moon. March’s full moon was known by Native American tribes as the Worm Moon, referring to the earthworms and grubs that emerge from their winter dormancy at this time of year, attracting robins and marking a sign of spring.