August isn’t known as a astronomy month – it’s challenging due to the bright, hot nights, and buggyness. If you are going on vacation this month, check out the skies in many places darker than our glowing suburbs, especially when our National Parks and Wilderness areas are reintroducing vacationers to the wonders of a dark sky so often masked in our cities.
Saturn has the evening sky pretty much all to itself, highest in the southwest at dusk. Being sideways from us, we get to peek around the side of the planet. In a telescope, the shadow of the planet is just visible on the rings, maximizing the 3D effect. Don’t neglect Saturn on hazy nights – the high pressure systems that concentrate our pollution into haze are the same nights when the bubbling jet stream is far away. Saturn’s largest moon, Titan, stands out near the planet, despite the glare from the wide-open rings. Among Saturn’s other moons, you may find it easier to find Saturn’s fourth-brightest moon, Iapetus, going from magnitude + 10 to +11 this month, as it moves from west of Saturn to passing north of Saturn on the 29th. Titan also passes to the north on the 7th and the 23rd.
Venus and Jupiter leave the evening sky. Venus stakes her claim as the morning star by the end of the month. She moves quickly from low in the west right after sunset at the start of the month. Venus is a crescent almost one arc second wide, seen best with optical aid in a bright sky. This closest plant to Earth this month gives the Sun a wide berth, passing 7.8 degrees to the south (below) the Sun on the 15th – 67.9 million miles from the Sun and 27.0 million miles from the Earth. Mercury passes Jupiter on its way out, closest on the 6thand 7th, very low in the west. Regulus is in the same area, but you’ll need binoculars to see it.
Uranus and Neptune are well placed in the middle of the night and pre-dawn hours. Pluto is still hanging out on the ‘teaspoon’ of Sagittarius, accessible in large telescopes, photobombed by the Moon on the 25th.
August’s Full Moon occurs less than 24 hours after closest approach to the Earth, so be aware of higher-than-normal tides for a few days after the 29th. Let’s hope for no landfalling hurricanes then (or late next month).
The International Space Station overflights start off being visible every 90 minutes or so all night and soon become visible before local midnight until the last week of the month.
More on next week’s Perseids meteor shower later!