Weekly Sky Report
The Griffith Observatory Sky Report
This is the Griffith Observatory Sky Report through July 9th, 2020. Here’s what’s happening in the skies of southern California.
Comet NEOWISE (C/2020 F3), discovered on March 27, swings within 27 million miles of the sun on July 3rd, when it is hidden in the sun’s glare. The first period during which it can be seen from the northern hemisphere occurs between July 4th and the 15th at the start of dawn. It is expected to be magnitude 0.5, only slightly fainter than the brilliant star Capella located just above it, although the comet’s light is not concentrated into a point as is the star’s, so you still will need to look carefully to see it.
The comet rises just as dawn starts, so there will be a narrow period for observation each morning, between 4:30 and 4:45 a.m., just before the sky gets too bright. It will be above the northeast horizon, and as mentioned, just below the bright star Capella in Auriga the Charioteer (the brightest star visible in the northeast, far to the left of the planet Venus). Venus is above east point of the horizon at the same time.
To see the comet, you will need a completely unobstructed view of the northeast horizon. Binoculars are recommended. Starting at 4:30 a.m., aim the binoculars at Capella, then tilt them lower so that the horizon is visible at the bottom of the field of view. Sweep back and forth a small amount, parallel to the horizon, until you spot the comet, which may at first appear as a fuzzy glowing patch with a tail pointing upwards, away from the direction of the sun.
From the 4th through the 9th, the comet moves less than a binocular field of view from the right to the left side of the portion of the horizon directly below Capella. Check the social media sources listed at the end of this message for helpful viewing information.
At mid-month, Comet NEOWISE will move into the evening sky. Although the comet is expected to fade somewhat by then, it will be better situated for viewing high in the sky and for as long as hours at a time. Griffith Observatory will then provide detailed observing information on its website.
July 4th is the full moon, and it is also the occasion of an extremely subtle eclipse, called a penumbral lunar eclipse. The penumbra is the fuzzy outer part of a shadow, and it results when the involved light source is not a point, as is the case with the sun. Normally the moon must be more than half immersed in Earth’s penumbra for it to have any effect on the appearance on the full moon. On this eclipse, however, only the upper 37 percent of the moon’s diameter will dip into the penumbra. If any effect is visible, it might be a slight dimming of the upper edge of the moon for a few minutes around mid-eclipse, at 9:29 p.m.
The bright outer planets Jupiter and Saturn form an eye-catching pair in the constellation Sagittarius the Archer. They are visible low in the southeast sky by 10:00 p.m., and they cross the meridian in the south within 25 minutes of one another, starting at 1:30 a.m. They are low in the southwest sky at dawn. Pale-yellow Jupiter is the brighter of the two planets, while Saturn, 6 degrees to the left of Jupiter, has a golden hue. The moon will pass by Jupiter and Saturn on July 5 and 6.
Orange planet Mars can be spotted low in the eastern sky by 1:30 a.m. At dawn it is 47 degrees high in the southeast sky, slightly above the point located midway from the horizon to the zenith—the point directly overhead. The waning gibbous moon is in-between Saturn and Mars on the 8th and 9th.
The brilliant planet Venus blazes low in the eastern sky just before dawn, and can be seen until the sun rises. The bright orange star next to it is Aldebaran in Taurus the Bull.
Because of measures in place that are intended to reduce the spread of the COVID-19 Corona virus, Griffith Observatory remains closed until further notice. Consequently, all public telescopes are closed, and all public events have been cancelled. Please check the Griffith Observatory homepage for current information and continued updates of the situation.
From Griffith Observatory, I'm Anthony Cook, and I can be reached at Anthony.Cook@lacity.org.