This comet just keeps on getting better. I was out again at 3:30 this morning and found Comet NEOWISE without even trying. Early on its head appears faint because of low altitude, but the tail is growing. I could easily see 3°-4°of it with the naked eye. Binoculars and photos doubled that. By 4 a.m., when the comet’s head was high enough to see clearly, it looked exactly like a star. I was also able to photograph the comet’s ion tail for the first time. Although I don’t know the length of this delicate appendage, the dust tail is at least 10 million miles (16 million km) long. Dust deposited in the orbit of the comet gives the tail a curved shape.
Ultraviolet light from the sun strips electrons from the gases released from vaporizing comet ice turning them into ions. If an atom or molecule gains or loses electrons it’s no longer “neutral” but said to be ionized. Ionized gases are strongly affected by magnetic fields bundled in the solar wind, the steady “breeze” of minute, subatomic particles blowing from the sun. By the way, these are the same specks that spark auroras. Comet ions are directed by the solar wind into a tail directly behind the comet.
As of July 10 NEOWISE is now magnitude 2, so it’s faded a little, but that’s been more than offset by the comet’s increasing altitude and the waning of the moon. If you have a telescope be sure to look at the comet for a powerful eyeful. Then, as dawn gets too bright to see NEOWISE well, swing your scope over to the waning moon for a look at some of the most incredible crater fields you’d ever want to see. After the moon, visit Mars. The moon passes to the lower right of the planet on July 11 and to the lower left on the 12th. Use high magnification and you’ll see the coolest feature Mars has to offer — its stunning south polar cap.
Richard Mitchell, one of our readers, reminds us that Venus is also at maximum brilliancy, another reason to get out at dawn. Coincidentally, it’s crossing the Hyades star cluster in Taurus, making for a pretty binocular sight.
I normally wake up around 8 in the morning but thanks to NEOWISE I’ve been rising around around 10 … with a ferocious appetite after being out all morning! Let the comet change your life a little. If nothing else it’ll take your mind off COVID-19 for a little while. Clear skies!