Two Comets Pass In The Night And More Amazing Cosmic Sights

Lionel Majzik captured comets C/2018 N2 ASASSN (top) and 260P/McNaught and a few faint galaxies to boot in a single frame on Sept. 7. Both comets were faint, about magnitude 12.5, but they are slowly brightening. To keep track of them, go to Seiichi Yoshida’s Weekly Information about Bright CometsLionel Majzik

Something very unusual happened during the wee hours of September 7. Two different comets appeared to almost cross paths in the sky. Despite appearances, the two objects weren’t physically close. Comet 260P/McNaught is very much in the foreground at a distance of about 56 million miles, while the look-a-like Comet C/2018 N2 ASASSN glowed from 238 million miles, more than four times further away.

They appeared closest in the early morning hours, separated by 20 arcminutes or about two-thirds the width of the full moon. Observers with 8-inch or larger telescopes would have seen both comets in the same field of view — a rare sight. I wish I’d been looking. Instead my eyes were fixed on the constellation Cepheus and its treasure trove of star clusters and double stars.

I love comets both for their beauty and their ever-changing appearance. You never know what to expect night to night. Some comets break up into smaller comets, while others have “outbursts” and brighten suddenly. I’ve even seen comets crumble and fade to nothing.

A comet’s bright inner core, called the false nucleus (the real one, the actual comet is hidden in a dusty cocoon), can brighten or change color, while tails can grow and multiply. Compared to the unchanging constellations, comets are the crazy kids of the sky.

Noctilucent clouds on Mars photographed by NASA’s Curiosity Rover on May 17, 2019. Noctilucent clouds appear on both Earth and Mars after sunset and before sunrise. They form at high altitudes where water condenses on meteor dust. NASA / JPL-Caltech / MSSS / Thomas Appere

Over the past few weeks I’ve come across several other amazing celestial scenes appearing on Facebook and other sites. Everything from a night-shining clouds on Mars to the Earth and moon caught between the rings of Saturn. Some are old, some are new. Enjoy.

The Earth and moon are two dots suspended in space between Saturn’s rings. NASA’s Cassini spacecraft grabbed this view on April 12, 2017 when Earth was 892 million miles (1.4 billion km) away. NASA / JPL-Caltech
Jupiter has rings, too! Made of fine rock particles unlike Saturn’s highly reflective icy chunks, they’re completely lost in the planet’s glare in normal light. These photos were taken in infrared light (we sense it as heat) in 1994 by the Infrared Telescope Facility in Hawaii in 1994 and cover a span of 2 hours. You can also see the cloud bands and couple of the planet’s small moons. It’s believed Jupiter’s rings are formed by material scattered from meteorite impacts on its family of 79 moons. J. Rayner (U. Hawaii), NSFCAMIRTFNASA
Part of Jupiter’s rings photographed by the Juno spacecraft on July 16, 2018. The part at top is in shadow. NASA / JPL-Caltech
This is my humble offering from planet Earth. I had been photographing the aurora when I turned around to see this amazing display of clouds that bears a striking resemblance to Einstein’s hair. Bob King
This daisy blossom of a crater has been cycling around on Facebook the past couple weeks. The amazing overhead view was taken by NASA’s Mars Reconnaissance Orbiter. The crater is only about a mile (1.5 km) across. Wind has sculpted sand dunes on its floor. Here’s a simulated video flyover of the scene. NASA / JPL-Caltech

5 Responses

  1. Edward M Boll

    I have an old star atlas. I used to spend time conjuncting stars with comets. If the same star conjuncted 2 in the same week. I had a possible 2 comets conjuncting. I gave that up about 15 years ago, because of a very busy schedule. With more time now, I would like to begin it again. The old star atlas was falling apart, and I thought that I had lost most of the pages, but the other day I found it, and it is almost all there.

    1. astrobob

      You’re right, Edward. Nothing bright in the region. I regret not seeing them. I was busy in Cepheus and because it was nearby I also looked at Africano, but it was so late by then (I did all my observing a midnight moonset) I didn’t check the other comets in Aries. Wish I had!

  2. allison

    I saw the two comets the following night, when they were separated by about 30 arc minutes. Both were small and faint but quite well-condensed as seen with my 12-inch telescope. I also found C/2018 W2 (Africano), which was brighter but much more diffuse, hence hardly any easier to see than the two comets in Aries.

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