Cosmic Space

What to know before you go comet-hunting

This summer’s sky spectacle is a shooting star that was discovered in March by NASA’s Near-Earth Object Wide-Field Explorer, or NEOWISE. Comet NEOWISE (also known as C/2020 F3) zoomed around the sun last week, and is now visible to the naked eye. But only if you know exactly where, when and how to look.

Although there’s lots of buzz about NEOWISE, this is no “great comet” — just a pretty good one. If you’re expecting to look up above your head and see a celestial portent of “Game of Thrones” proportions, you’re going to be disappointed.

But if you’re angling to see this season’s most-talked-about sky show with your own eyes, here are five strategies to maximize your chances:

Go late or go early: Because it’s so soon after the northern solstice, the celestial alignments make it theoretically possible to see Comet NEOWISE in morning or evening skies, with emphasis on the word “theoretically.”

For the next few days, the comet will be higher in the sky in the morning, which means predawn viewing is preferred. The best time is around 3 to 4 a.m.; the farther north you are, the earlier you should get up. Around July 15, the comet’s outward trajectory from the sun will turn it into more of an evening star, with prime time coming at 10:30 p.m., about an hour and a half after sunset.

Look north: Your viewing spot should have an unobstructed view to the northern horizon — to the northeast for morning viewing, or to the northwest for the evening. To find optimal views of the horizon, scan Google Maps (with Street View). And to figure out exactly where to look in the sky, study the charts from Sky & Telescope,, The Sky Live, Heavens Above and EarthSky.

Comet NEOWISE should be visible in the northeast by 3 a.m. July 11 — close to the horizon and to the left of Venus, the brightest object in eastern skies.

Seek clarity: The fact that NEOWISE is so close to the horizon means that sky conditions are crucial. There’s a good chance the comet could be lost in hazy or humid skies. And if there are clouds stretching across the horizon, that could be a deal-breaker. Finding out you’re clouded out at 3 a.m. is a truly rude awakening.

To determine if the forecast is favorable, click on over to, focus in on your viewing area and select “Sky Cover (%)” from the drop-down menu. Then move the slider bar to your planned viewing time (for example, “At Jul 11, 3 a.m.”) and check whether conditions are expected to be blue (set your alarm) or gray (sleep in).

Bring binoculars: Although NEOWISE is bright enough for naked-eye viewing, your naked eyes will see it pretty much as a fuzzy star. To make out the comet’s tail clearly, you’ll probably need to break out the binoculars or a telescope.

Skywatchers have been putting up some impressive pictures of NEOWISE and its double tail — a curving tail of cosmic dust illuminated by the sun, plus a dimmer, bluish tail of ions streaming straight out. You just have to remember that those photos are typically enhanced or stacked to bring out details you won’t be able to see with your own eyes.

Be realistic: Most celestial phenomena are subtler than the hype makes them out to be, so don’t get frustrated if that turns out to be the case for NEOWISE. While you’re out there comet-hunting, take a moment to check out other celestial wonders — ranging from the International Space Station and passing satellites to the moon, planets and meteors.

Even if you miss seeing NEOWISE with your naked eyes, you can still connect with the comet by checking out the views from the space station, NASA’s Parker Solar Probe and the scores of dedicated comet-hunters whose photos appear on, EarthSky and other online galleries.

Update for 2 p.m. PT July 13: I discovered that 4 a.m. is really too late to look for the comet in northern-latitude locations (like Seattle). I totally missed seeing it at 4 a.m. on July 11 — but had much better luck at 3 a.m. on July 13, when it was still dark enough to spot NEOWISE in advance of the predawn glow. I’ve changed the time references in this story for the benefit of those still trying to catch sight of the comet before dawn.


Tech titan Nathan Myhrvold revisits asteroid flap

Image: Nathan Myhrvold
Nathan Myhrvold shows off a fragment of the Chelyabinsk meteorite in his office at Intellectual Ventures in Bellevue, Wash. (GeekWire photo by Alan Boyle)

Nathan Myhrvold is back, and this time he’s got peer review on his side.

Two years ago, the Seattle tech pioneer tangled with NASA and the scientists behind an infrared sky survey mission known as NEOWISE, over a data set that cataloged the characteristics of more than 157,000 asteroids.

In a lengthy assessment, Myhrvold said the NEOWISE team had made flawed and misleading correlations between the brightness and the size of asteroids.

In response, NASA pointed to mistakes in Myhrvold’s critique and noted that his claims hadn’t gone through scientific peer review. “It is important that any paper undergo peer review by an independent journal before it can be seriously considered,” NASA said at the time.

If that’s so, then it’s time for serious consideration. Myhrvold’s paper, “An Empirical Examination of WISE/NEOWISE Asteroid Analysis and Results,” has now been published (with corrections of what he acknowledged were mistakes) in the peer-reviewed journal Icarus.

And that’s not all.

Get the full story on GeekWire.


Looking for Planet 9? There’s an app for that

Image: Planet X
An artist’s conception shows Planet X, a.k.a. Planet Nine. (Credit: Robin Dienel / Carnegie Inst.)

Citizen scientists can join an online hunt for icy worlds, brown dwarfs and other yet-to-be-discovered objects beyond the orbit of Neptune, using a technique that’s not all that different from the method that led to Pluto’s discovery 87 years ago.

“Backyard Worlds: Planet 9” could even lead to the discovery of a super-Earth that may (or may not) be hidden on the solar system’s far frontier. The icy world known as Planet Nine or Planet X is only theoretical for now, but its existence would explain some of the puzzles surrounding the weird orbits of some far-out objects.

Get the full story on GeekWire.


NASA fires back in spat over asteroid data

Image: WISE spacecraft
An artist’s conception shows NASA’s Wide-field Infrared Survey Explorer, or WISE. WISE observations of near-Earth objects were analyzed for the NEOWISE mission. (Credit: NASA)

BELLEVUE, Wash. – NASA issued a statement today disputing Seattle tech icon Nathan Myhrvold’s critique of asteroid data analysis from the space agency’s NEOWISE mission.

The statement follows up on reports published this week by GeekWire and othermedia outlets. In those reports, Myhrvold said NEOWISE’s analysis relied on flawed statistical calculations, which resulted in incorrect or highly uncertain measurements for thousands of asteroids.

When GeekWire showed Myhrvold’s critique to scientists associated with NEOWISE and the Wide-field Infrared Survey Explorer, they identified what they said were serious errors – including misinterpretations of NEOWISE’s methods and an apparent confusion between radius and diameter in one key equation. GeekWire’s report on Monday referred to those problems, as well as Myhrvold’s acknowledgment of mistakes.

Today’s NASA statement refers to those errors as “mistakes that an independent peer review process is designed to catch.”

“While critique and re-examination of published results are essential to the scientific process, it is important that any paper undergo peer review by an independent journal before it can be seriously considered,” NASA said. “This completes a necessary step to ensure science results are independently validated, reproducible and of value to the science community.”

Get the full story on GeekWire.


Nathan Myhrvold stirs up an asteroid argument

Image: Nathan Myhrvold
Nathan Myhrvold shows off a fragment of the Chelyabinsk meteorite in his office at Intellectual Ventures in Bellevue, Wash. (GeekWire photo by Alan Boyle)

BELLEVUE, Wash. – Millionaire techie Nathan Myhrvold is used to stirring up controversy over issues ranging from patent licensing to dinosaur growth rates, but now he’s weighing in on an even bigger debate: the search for potentially hazardous asteroids.

In a 110-page research paper posted to the ArXiv pre-print server and submitted to the journal Icarus for peer-reviewed publication, Myhrvold says the most comprehensive survey of near-Earth asteroids ever done, known as NEOWISE, suffers from serious statistical flaws.

“They made a set of numbers that look right, They have what Stephen Colbert calls ‘truthiness.’ But that doesn’t mean they are right,” he told GeekWire today during an interview at the Bellevue headquarters of Intellectual Ventures, the company he founded.

On the other side of the debate, NEOWISE’s principal investigator, Amy Mainzer of NASA’s Jet Propulsion Laboratory, says it’s Myhrvold’s numbers that don’t look right.

“The paper contains multiple mistakes, including the confusion between diameter and radius (which is by itself enough to render the results wrong),” she wrote in an email to GeekWire. “Nonsensical asteroid diameters are presented throughout by the author.”

Mainzer noted that Myhrvold’s paper has not yet gone through formal peer review.

Get the full story on GeekWire.