Watch a Comet Fly Away Like the Dinosaurs Wish They Could

  • Jul 21, 2020
  • Blog Post

Through the end of July, we have a rare opportunity to watch a massive comet miss our planet(sorry Dinosaurs!) and put on a beautiful show in the process. The comet, C/2020 F3, was first discovered by the NEOWISE space telescope on March 27.

As you read this, this five-kilometer hunk of ice and carbon is creating a dazzling, nightly display across the Northern Hemisphere for astronomers and casual stargazers alike. C/2020 F3 will get progressively brighter and higher in the sky until NEOWISE makes its closest approach on the night of July 23. Get out there and take a look: if you miss it, you'll have to wait a cool 6,800 years to see it again.

Luckily, STK is here to make sure that doesn’t happen! With the JPL Horizons Interface Plugin and STK, you can visualize the flight of C/2020 F3 through our solar system for yourself.

Check out our knowledge article about the plugin ( to learn how to load ephemeris data straight from the JPL Horizons Tool into STK. C/2020 F3 Orbit and Location – 07/17/20 To demonstrate how to do this, I loaded the comet’s ephemeris into STK and then added an umbra lighting constraint and a direct sunlight constraint to my place object and comet, respectively. This will ensure that I get the best possible visibility of the comet.

Finally, I added a five-degree minimum elevation angle constraint on my place object to ensure that I can see the comet over nearby hills. Once I computed access between my place (AGI Headquarters) and the comet, I was able to determine my best viewing window from an Azimuth-Elevation-Range(AER) report. The result: at 8:20 EST on July 23, my best viewing window will begin and I’ll be able to see the comet a full 37 degrees above the horizon!

Simulated view from AGI Headquarters at sunset on July 23, 2020

Get out there and look to the heavens!