11 Photos From the Opportunity Rover's Mission on Mars

NASA
NASA

In 2004, the rover Opportunity landed on Mars. Originally intended to serve a mere 90-day mission, the rover instead beamed back scientific discoveries for 15 years. But since a massive dust storm in 2018, the rover Opportunity ceased sending data—and now, NASA has declared its groundbreaking mission complete. (Its twin rover, Spirit, ended its mission in 2011.) Opportunity is the longest-serving robot ever sent to another planet. Let's celebrate Opportunity's Mars mission with a look at the images it captured.

1. Opportunity rover gets its first 360° shot.

NASA/JPL/Cornell 

This 360° panorama, comprised of 225 frames, shows Mars as it was seen by the Opportunity rover on February 2, 2004. You can see marks made by the rover's airbags, made as Opportunity rolled to a stop. Here's a larger version of the photo.

2. Opportunity rover finds a meteorite.

NASA/JPL/Cornell

This meteorite, found by Opportunity on January 19, 2005, was the first meteorite ever identified on another planet. The rover's spectrometers revealed that the basketball-sized meteorite was composed mostly of iron and nickel.

3. Opportunity rover shoots the Erebus Crater and drifts.

NASA/JPL-Caltech/Cornell

On October 5, 2005—four months after Opportunity got stuck in an area NASA nicknamed "Purgatory Dune"—the rover skirted wind-deposited drifts in the center of the Erebus Crater, heading west along the outcrop (the light-toned rock) on the crater's rim, and snapped this photo with its PanCam.

4. Opportunity rover captures Martian rock layers.

NASA/JPL/Cornell

Located on the western ledge of the Erebus Crater, this ledge—called "Payson"—has a diverse range of primary and secondary sedimentary layers formed billions of years ago. According to NASA, "these structures likely result from an interplay between windblown and water-involved processes." Opportunity snapped this photo on April 5, 2006.

5. Opportunity rover comes to Cape Verde.

NASA/JPL-Caltech/Cornell

On October 20, 2007, Opportunity celebrated its second Martian birthday (one Martian year = 687 Earth days) by snapping this photo of Cape Verde, a promontory that juts out of the wall of the Victoria Crater. Scattered light from dust on the front sapphire window of the rover's camera created the soft quality of the image and the haze in the right corner.

6. and 7. Opportunity rover is hard at work on Marquette Island.

NASA/JPL-Caltech

This photo shows Opportunity approaching a rock called "Marquette Island" on November 5, 2009. Because its dark color made it stick out, the rover team referred to the rock—which investigations suggested was a stony meterorite—as "Sore Thumb." But it was eventually renamed, according to NASA, using "an informal naming convention of choosing island names for the isolated rocks that the rover is finding as it crosses a relatively barren plain on its long trek from Victoria Crater toward Endeavour Crater."

On November 19, 2009, the rover used its rock abrasion tool to analyze a 2-inch diameter area of Marquette, which scientists called "Peck Bay."

8. Opportunity rover encounters SkyLab Crater.

NASA/JPL-Caltech

Opportunity snapped a photo of this small crater, informally called Skylab, on May 12, 2011. Scientists estimate that the 30-foot crater was formed within the past 100,000 years. Click the photo for a larger version. You can also see the crater in stereo if you have a pair of anaglyph glasses!

9. Opportunity rover sees its shadow.

NASA/JPL-Caltech

On its 3051st day on Mars (August 23, 2012), Opportunity snapped this photo of its own shadow stretching into the Endeavour Crater.

10. Opportunity rover sees its first dust devil.

NASA/JPL-Caltech/Cornell University/Texas A&M

Though its twin rover, Spirit, had seen many dust devils by this point, Opportunity caught sight of one for the first time on July 15, 2010.

11. Opportunity rover snaps a selfie.

NASA/JPL-Caltech/Cornell University/Arizona State University

A girl sure can get dusty traversing the Martian plains! Opportunity snapped the images that comprise this self-portrait with its panoramic camera between January 3 and January 6, 2014, a few days after winds blew off some of the dust on its solar panels. The shadow belongs to the mast—which is not in the photo—that the PanCam is mounted on.

10 Rad Gifts for Hikers

Greg Rosenke/Unsplash
Greg Rosenke/Unsplash

The popularity of bird-watching, camping, and hiking has skyrocketed this year. Whether your gift recipients are weekend warriors or seasoned dirtbags, they'll appreciate these tools and gear for getting most out of their hiking experience.

1. Stanley Nesting Two-Cup Cookset; $14

Amazon

Stanley’s compact and lightweight cookset includes a 20-ounce stainless steel pot with a locking handle, a vented lid, and two insulated 10-ounce tumblers. It’s the perfect size for brewing hot coffee, rehydrating soup, or boiling water while out on the trail with a buddy. And as some hardcore backpackers note in their Amazon reviews, your favorite hiker can take the tumblers out and stuff the pot with a camp stove, matches, and other necessities to make good use of space in their pack.

Buy it: Amazon

2. Osprey Sirrus and Stratos 24-Liter Hiking Packs; $140

Amazon

Osprey’s packs are designed with trail-tested details to maximize comfort and ease of use. The Sirrus pack (pictured) is sized for women, while the Stratos fits men’s proportions. Both include an internal sleeve for a hydration reservoir, exterior mesh and hipbelt pockets, an attachment for carrying trekking poles, and a built-in rain cover.

Buy them: Amazon, Amazon

3. Yeti Rambler 18-Ounce Bottle; $48

Amazon

Nothing beats ice-cold water after a summer hike or a sip of hot tea during a winter walk. The Yeti Rambler can serve up both: Beverages can stay hot or cold for hours thanks to its insulated construction, and its steel body (in a variety of colors) is basically indestructible. It will add weight to your hiker's pack, though—for a lighter-weight, non-insulated option, the tried-and-true Camelbak Chute water bottle is incredibly sturdy and leakproof.

Buy it: Amazon

4. Mappinners Greatest 100 Hikes of the National Parks Scratch-Off Poster; $30

Amazon

The perfect gift for park baggers in your life (or yourself), this 16-inch-by-20-inch poster features epic hikes like Angel’s Landing in Zion National Park and Half Dome in Yosemite National Park. Once the hike is complete, you can scratch off the gold foil to reveal an illustration of the park.

Buy it: Amazon

5. National Geographic Adventure Edition Road Atlas; $19

Amazon

Hikers can use this brand-new, updated road atlas to plan their next adventure. In addition to comprehensive maps of all 50 states, Puerto Rico, Canada, and Mexico, they'll get National Geographic’s top 100 outdoor destinations, useful details about the most popular national parks, and points on the maps noting off-the-beaten-path places to explore.  

Buy it: Amazon

6. Adventure Medical Kits Hiker First-Aid Kit; $25

Amazon

This handy 67-piece kit is stuffed with all the things you hope your hiker will never need in the wilderness. Not only does it contain supplies for pain, cuts and scrapes, burns, and blisters (every hiker’s nemesis!), the items are organized clearly in the bag to make it easy to find tweezers or an alcohol wipe in an emergency.

Buy it: Amazon

7. Hiker Hunger Ultralight Trekking Poles; $70

Amazon

Trekking poles will help increase your hiker's balance and stability and reduce strain on their lower body by distributing it to their arms and shoulders. This pair is made of carbon fiber, a super-strong and lightweight material. From the sweat-absorbing cork handles to the selection of pole tips for different terrain, these poles answer every need on the trail. 

Buy it: Amazon

8. Leatherman Signal Camping Multitool; $120

Amazon

What can’t this multitool do? This gadget contains 19 hiking-friendly tools in a 4.5-inch package, including pliers, screwdrivers, bottle opener, saw, knife, hammer, wire cutter, and even an emergency whistle.

Buy it: Amazon

9. RAVPower Power Bank; $24

Amazon

Don’t let your hiker get caught off the grid with a dead phone. They can charge RAVPower’s compact power bank before they head out on the trail, and then use it to quickly juice up a phone or tablet when the batteries get low. Its 3-inch-by-5-inch profile won’t take up much room in a pack or purse.

Buy it: Amazon

10. Pack of Four Indestructible Field Books; $14

Amazon

Neither rain, nor snow, nor hail will be a match for these waterproof, tearproof 3.5-inch-by-5.5-inch notebooks. Your hiker can stick one in their pocket along with a regular pen or pencil to record details of their hike or brainstorm their next viral Tweet.

Buy it: Amazon

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Asteroid, Meteor, Meteorite, and Comet: What's the Difference?

A mosaic image of asteroid Bennu
A mosaic image of asteroid Bennu
NASA's Marshall Space Flight Center, Flickr // CC BY-NC 2.0

By Sabrina Stierwalt, Ph.D., Quick and Dirty Tips

Adding up all of the mass in every asteroid in our entire solar system totals only less than the mass of our moon. Despite their small physical size, however, these space rocks offer important clues as to how our solar system formed. The terms asteroid, meteor, meteorite, and even comet are often used interchangeably ... but what is the difference?

What is an asteroid?

Asteroids are rocky objects smaller than planets that are left over from the formation of our solar system. When the cloud of gas and dust collapsed to form our sun, much of the remaining material went into forming the rocky terrestrial and gas giant planets orbiting our star. Smaller dust fragments that never made their way into planets are left behind as asteroids.

Of the millions of known asteroids, the largest is Ceres, 584 miles (940 kilometers) wide, although Ceres has been recently reclassified as a dwarf planet. Luckily we do not expect to cross paths with this Texas-sized solar system body any time soon. NASA tracks a subset of asteroids, called "near Earth objects" or NEOs, whose trajectories have been nudged by the gravitational push and pull of nearby planets enough so that they may pass close to Earth.

Thanks to infrared surveys of the sky like NASA’s WISE and NEOWISE missions, we know of roughly 1000 near-Earth asteroids that are larger than 0.6 miles across (or 1000 meters) and 1500 more that are between a third of a mile and 0.6 miles across (from 500 to 1000 meters). Smaller near-Earth asteroids, both known to exist and predicted based on statistical analysis, number in the 18,000s.

Most are not round like planets but rather irregular in shape, sometimes due to repeated impacts over time. They are also known to orbit each other, making their way around the sun in pairs or small groups. They are not large enough to hold onto their own atmospheres and their compositions vary, mostly due to the location where they were formed, in particular how far away they were from the sun when they originated.

Most asteroids reside in the asteroid belt, the space between the orbits of Mars and Jupiter, most likely because the gravitational pull of Jupiter prevented them from accumulating into a larger planetary system. Some asteroids are also found in the orbital paths of planets like Earth. Until recently all known asteroids orbited our sun as members of our solar system, but that changed in October 2017 when astronomers discovered the first interstellar visitor just passing through our solar neighborhood. Named 'Oumuamua, which comes from the Hawaiian word for “scout,” the asteroid has an unusual elongated shape (800 by 100 feet in size) and is moving too fast to be captured by our sun’s gravitational pull. That means 'Oumuamua will eventually leave us and continue on its journey through interstellar space.

What is a comet?

Comets are also composed of material left over from the formation of our solar system and formed around the same time as asteroids. However, asteroids formed toward the inner regions of our solar system where temperatures were hotter and thus only rock or metal could remain solid without melting. Comets formed at farther distances from the Sun, beyond what we call the frost or snow line and past the orbits of Mars and Jupiter, where temperatures were low enough for water to freeze.

Comets are thus chunks of frozen gas, rock, ice, and dust that orbit our sun, earning them the nickname of dirty snowballs. They are identified by their tails which consist of trailing jets of gas and dust that has been melted off as a comet approaches too close to the sun.

What is a meteor and a meteorite?

A meteor is simply an asteroid that attempts to land on Earth but is vaporized by the Earth’s atmosphere. The resistance on the rock due to the Earth’s atmosphere causes its temperature to rise. We sometimes see the glowing hot air created by these burning meteors and dub them “shooting stars.” Meteor showers occur when the Earth passes by many meteors at once. For example, if chunks of a comet melt off as it passes close to the sun, this debris can be left behind to later dazzle us Earthlings with a meteor shower.

Meteorites are meteors that survive the dive through the Earth’s atmosphere and manage to land on the surface of our planet. They are typically composed of either iron or stone, i.e. a mix of oxygen, silicon, magnesium, iron, and other elements.

Studying asteroids helps us understand the formation of our solar system and how our planet came to be. We don’t just have to wait for meteorites to find us to know more about their composition, however. The OSIRIS-Rex mission to the asteroid Bennu aims to take samples from the asteroid and bring them back to Earth. You can learn more about why Bennu was chosen for such a special mission on the OSIRIS-Rex mission page.

A version of this article was originally published on Quick and Dirty Tips as Asteroid, Meteor, Meteorite, and Comet: What's the Difference?
Read more from Quick and Dirty Tips.

About the author

Dr. Sabrina Stierwalt earned a Ph.D. in astronomy and astrophysics from Cornell University and is now a professor of physics at Occidental College.