What's Up: June 18-25 - Jared May

What’s Up This Third Week of June

The forecast this week looks quite promising for some clear or partially clear nights. The temperature in the hours following sunset will be quite comfortable, hovering in the low 70s. The sun sets this week around 9 PM so be ready with your stargazing gear by 10 PM. Haze from Canadian forest fire smoke might be a factor. If skies are milky white or slightly brown near the horizon, then conditions will be less favorable for pristine views of the stars.

Be on the lookout for the new moon, Saturn in retrograde, a Mars-Venus-Moon meetup, overhead satellites, and the summer solstice. 

This Sunday, June 18th, marks the new moon. This is great news for stargazers and astrophotographers alike since the sky will be free of the moon’s glow that washes out faint deep-sky objects. The moon will be “above” the sun by nearly 10 degrees. When this apparent separation between the new moon and the sun closes to zero degrees, that is a solar eclipse. There are four types of solar eclipses: total, annular, partial, and hybrid. There will be an annular solar eclipse in October (2023) and a total solar eclipse in April (2024), both of which cross large areas of the United States. 

You can’t see the “new moon” but it’s there, in the sky, near the blazing light of the sun.

Sunday also marks the day that Saturn shifts from its “forward” motion to its backward motion, or “retrograde” path in the sky. This odd behavior is because the Earth is closer to the sun by tens of millions of miles and so we rotate around the sun quicker. When the Earth passes a special point in its orbit relative to any of the outer planets (that all orbit the sun slower) the apparent velocity of that planet relative to background stars is zero and hence the planet appears to be stationary before starting its retrograde motion. The same illusion also applies to the inner planets, Mercury and Venus.

Saturn is visible in the morning sky right now and will be best seen in the evening in the fall.

Why the planets appear to move backwards, or retrograde, from time to time.

Starting Tuesday, June 20th, look in the western sky about an hour after sunset to spot Mars and Venus nearing each other. Throughout the week the thin waxing crescent moon will be passing through this planetary duo. On Wednesday, June 21st, the moon will be above Venus by only 3 degrees. 

The brilliant Venus points the way to the fainter Mars, to its upper left, this week. They be at their closest on the 20th and 21st.

Look up in the night sky for a few minutes and you are extremely likely to see something that looks like an airplane but is silent and has no blinking lights – this is a satellite (likely in low Earth orbit). Some of these satellites are over 1,000 miles overhead and are visible because sunlight is reflecting off their large solar panel arrays or their reflective mylar covers. Common satellite tracking websites have something like 7,700 satellites in their database. About 4,200 of those are the SpaceX Starlink satellites. A careful eye may spot multiple satellites visible overhead at the same time. [IMAGE: https://www.satflare.com/home.asp]

A image illustration the astonishing number of satellites now in orbit.

Wednesday, June 21st, marks the 2023 summer solstice. This is when the sun reaches its highest apparent point in the northern hemisphere and hence gives us the day with the most amount of daylight. Past June 21st, the days will get shorter and shorter until the winter solstice on December 21st.

Get outside and enjoy the multiple clear nights (fingers crossed!) this week. The temperature will be comfortable and hopefully won’t lead to dew buildup on your binoculars or telescopes. Point out to your stargazing friends the new moon, Saturn appearing to move backward, a planetary meetup, satellites passing overhead, and enjoy the longest day of the year.

Clear Skies!