Nation & World News

Jupiter Or Bust, But First A Quick Fly-By Of Home

By Joe Palca on October 9th, 2013

After traveling for more than two years and some 1 billion miles, NASA’s Juno mission to Jupiter is back where it started. Almost. At 3:21 p.m. ET Wednesday, the Juno space probe will be 347 miles away from Earth, just above the southern tip of Africa.

(As an aside, at around 11:30 a.m. ET, it was more than 90,000 miles away.)

It’s not that Juno got homesick — the return to Earth was a necessity. To send it on a direct path to Jupiter would have required a more powerful rocket than the United Launch Alliance Atlas V-551. But that was the rocket that was available, so mission managers created a trajectory that uses Earth’s gravity as a kind of slingshot, adding the oomph needed to set the spacecraft on course to its destination.

The Messenger spacecraft took a similarly circuitous route to reach Mercury’s orbit, a journey that took nearly eight years. Check out this video of Messenger’s path.

So will Juno be visible to people on Earth? According to the website Heavens-Above.com:

“If you know where to look and live in the right part of the world, you will have a chance to see it through binoculars or a telescope. Lucky observers who live in the extreme south-west of Africa (e.g. Cape Town) could even see it with the naked eye just before it enters the Earth’s shadow.”

Juno’s primary mission is to measure the gravity and magnetic fields of the gas giant. The data should help scientists determine whether the planet has a solid core. It will be the first mission to fly low over Jupiter’s poles. Actually, Juno will fly just below the planet’s thin rings and just above the cloud tops.

But while it’s still nearby, ham radio operators around the world have been invited to try a little experiment. Using Morse code, hams will send the message “hi” at frequencies in the 10 meter amateur band. The message will be sent very, very slowly. Each dot in the dot-and-dash code is supposed to last 30 seconds, so it will take 10 minutes to send the word “hi” once.

Why this little experiment? Well, largely it’s to engage the public in a NASA mission. There is a scientific point, though. It will give Juno mission managers a chance to test out instruments designed to measure plasma and radio waves. A big goal of the Juno mission is to develop a better understanding of the auroras at Jupiter’s poles.

It will take nearly three years for Juno to reach Jupiter once it leaves Earth. The expected arrival date is July 4, 2016.

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

This entry was posted in News from NPR. Bookmark the permalink.

Comments are closed.

 

More Stories in News from NPR

Seattle Cuts Public Transportation Fares For Low-Income Commuters

Low-income riders can now qualify for a program that will slash their fares by more than half of peak rates. But the cost will be offset by fare increases for everybody else.


Task Force Calls For Independent Probes Of Police-Involved Shootings

The President’s Task Force on 21st Century Policing also emphasized the need for better training and equipment, including bulletproof vests. But it stopped short of insisting police wear body cameras.


A photo from by the Taronga Zoo shows a six-month-old Quokka, a marsupial that has made it a hit on social media.

Cuteness Break: The Genial Quokka Steals Scenes And Hearts

In many photos from an Australian island, the marsupial appears front and center, adding its enigmatic smile to images of happy tourists.


A 33-foot-long tunnel found in Toronto, Ontario, is pictured in this handout photo provided by Toronto Police.

Riddle Of Mysterious Tunnel Solved, Toronto Police Say

Two men claimed they dug the tunnel for “personal reasons,” police say. The case has since been closed.


Artist Nelson Shanks' 2005 portrait of former President Clinton, which hangs at the Smithsonian Institution's National Portrait Gallery.

Clinton’s Portrait Has Hint Of Lewinsky’s Blue Dress, Artist Says

Nelson Shanks tells the Philadelphia Daily News a shadow on the left side of the painting represents not only the infamous dress, but also “a shadow on the office he held, or on” President Clinton.


Thank you for your support

WUFT depends on the support of our community — people like you — to help us continue to provide quality programming to North Central Florida.
Become a Sustainer
I want to support FM 89.1/NPR
I want to support Florida's 5/PBS
Donate a Vehicle
Day Sponsorship Payments
Underwriting Payments