Comet NEOWISE Zips Closest To Earth Today, Heads South

Comet NEOWISE appears in the window of Rick Klawitter’s bedroom in Port Angeles, Wash. on July 15. This is a direct photograph, not a composite. At the time, the brightness of outdoor twilight was very similar to the ambient light in the room. Very cool idea and one of my favorite comet photos. Details: Nikon D3s / ISO 12800, 24 mm at f/8, 30-second exposure. Rick Klawitter

Around 8 p.m. CDT Weds. July 22 Comet NEOWISE makes its closest approach to the Earth at a distance of 64.3 million miles (103.5 million km). That’s about two-thirds the distance between the Earth and sun, so not very close. Normally you’d think the comet would be brightest now but instead the it’s been slowly fading since early July. Why? NEOWISE sailed nearest the sun on July 3 and has been receding from it ever since. Since the comet shines by reflected sunlight, the farther it gets from the sun the fainter it becomes. Still, it doesn’t hurt that NEOWISE has been closing in on Earth for the past few weeks — that’s certainly helped to slow its fading.

Comet NEOWISE is currently traveling well above the plane of the solar system, defined by Earth’s orbit around the sun. We look “up” to see it from our vantage point. The map shows the comet’s position for July 22, 2020 (CDT), the date of its closest approach to Earth. NASA / HORIZONS with additions by the author

After today it heads back to the Oort Cloud not to be seen again in these parts for another 6,800 years. NEOWISE is currently about magnitude 3.5, a magnitude and a half or about four times fainter than it was a week ago. Yet the comet still hangs in there. While not as obvious in twilight as it once was, it’s still easy to see at nightfall in a dark sky with a long, delicate dust tail.

The Big Dipper continues to lead the way to the comet through the end of July. Positions are marked every three nights. Stellarium with additions by the author

A pair of binoculars remains the instrument of choice when it comes to getting the best look at NEOWISE. That’s especially true now that the waxing moon has entered the picture. I’m often asked how long we’ll see the comet. It should remain visible from a dark sky without optical aid up until about August 1 — theoretically. But light from the half-moon will make this a challenge starting July 27-28. For the best views of the comet go out now through July 26.

From August 1-15 binoculars will still show the comet, but the tail will become increasingly faint and difficult to make out. If predictions hold true you’ll need a modest-sized telescope to pick up the comet in late August and a considerably larger one by mid-September. Throughout, NEOWISE moves southward, passing from Ursa Major into Coma Berenices (Queen Berenice’s hair) on July 29th. After a brief stay in Boötes in early August it arrives in Virgo on the August 15th. The comet’s altitude remains roughly the same throughout its evening appearance — about 25° high at nightfall from 40° N latitude.

The comet tracks upward from the western horizon for observers in the Southern Hemisphere beginning next week. Stellarium

Next week brings good news for Southern Hemisphere skywatchers when we finally get to share our fuzzy friend with comet lovers on the other end of the Earth. If you’re one of them, watch for NEOWISE low in the western sky toward the end of evening twilight. For northerners the comet is still an easy naked-eye object from dark skies, looking like a smoky streak with a broad, faint tail that extends upward toward the bowl of the Big Dipper. From the city and suburbs the comet is faint and best viewed in binoculars.

Comet NEOWISE appears below the Big Dipper during late twilight on Wednesday, July 22. The photo nicely matches its naked-eye appearance at the time. Bob King

6 Responses

    1. Hi Tim,
      Great question. I’ve seen no research to indicate it will, but I would highly doubt it because the comet’s orbit doesn’t cross that of Earth. For a meteor shower to happen Earth and the comet debris have to intersect.

  1. Kurt moeller

    Dear Bob King. Thank you for your excellent updates on this beautiful comet! This by far is the most beautiful since hale bop in 1997. That I’ve seen anyway. My whole family got out last night in a dark spot to look at it. It was the first time any of them ever observed a comet! I just kept badgering the heck out of them until they gave in and came outside. After being wowed by this comet we all turned the stuff around and checked out Jupiter and Saturn and a nice nebula in the Milky Way! Firsts for all of them. I wish I could get more folks to do this. Nothing is more deeply rewarding. I’m pretty sure the comet was in the third magnitude because it was so much easier to see than love joy was a few years back which was briefly in the fourth magnitude with much better placing. Maybe even second magnitude it was bright! Very easy object.

    1. Thank you for the kind words, Kurt! And I’m delighted you got the whole family out. They won’t forget it. I share your sense of joy and reward at the sight 🙂

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