One year ago, Ingenuity took its first flight on Mars. And its story since is that of a real-world little helicopter that could.

Ingenuity traveled to the Red Planet attached to the belly of NASA’s Perseverance rover, and both arrived in Jezero crater last February (SN: 2/17/21). About six weeks later, the helicopter began what was meant to be only a 30-day technology demonstration to see if flight is possible in the thin Martian atmosphere.

It proved it could fly — and then some (SN: 4/19/21). Over the next couple weeks, Ingenuity took four more flights, each time going a bit farther, a bit faster and a bit higher. After those first test flights, Ingenuity’s mission morphed from a technology demonstration to operations, helping Perseverance traverse the surface by scouting the terrain ahead (SN: 4/30/21; SN: 12/10/21).

Sign Up For the Latest from Science News

Headlines and summaries of the latest Science News articles, delivered to your inbox

Thank you for signing up!

There was a problem signing you up.

Before the helicopter arrived, scientists had two perspectives of Mars. “We have pictures taken from orbit around Mars, and then we have pictures taken by rovers driving on the ground,” says planetary scientist Kirsten Siebach of Rice University in Houston, who is not part of the Ingenuity team. “But now this has opened up an entirely new perspective on Mars.” 

Ingenuity has surpassed all expectations. It has shown not only that flight is possible but also what is possible with flight. Science News discussed the helicopter’s big moments, collaboration with the rover and upcoming flights with Håvard Fjær Grip. He’s Ingenuity’s chief pilot and an engineer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. His answers were edited for length and clarity.

SN: What does the “chief pilot” for a helicopter on another planet do?

Grip: The biggest part of the job is planning the flights. Ingenuity doesn’t know where it is or where it wants to go when it wakes up, so all of those decisions are made here [on Earth]. Every maneuver that the helicopter makes during the flight is planned here on the ground first, and then we uplink the instructions to Ingenuity. When it comes time to fly, it uses its onboard software to follow our instructions as precisely as possible.

On April 19, 2021, Ingenuity Chief Pilot Håvard Fjær Grip (pictured) logged the first flight on another world in an official logbook.JPL-Caltech/NASA

SN: Ingenuity has completed 25 flights. Can you talk about how it’s exceeded expectations?

Grip: It is pretty great. We came there expecting to perform at most five flights within the 30-day window. And all of that was going to happen within in a small area that we carefully selected. We spent weeks figuring out exactly where to place the helicopter, studying these tiny little rocks. Everything was mapped out. And then things went so well when we started flying that almost immediately people started thinking, “Wow, let’s try to make use of this beyond those five flights.”

We started this next phase where, to be useful at all, we had to fly away from this carefully selected area. I’m really proud of that. We’ve been able to take this technology that was designed for this very limited mission and extend it to go and land different places on Mars and to travel across terrain that, originally, we had never planned on traveling across.

It’s lasted now for over a year since we deployed it to the surface. I don’t think any of us had imagined that that would be possible.

SN: Have there been any specific flights that have stood out to you?

Grip: Obviously, the first flight. That was the most important flight; it still is. We had a more challenging [time on] flight six. It became exciting, because we had an anomaly during the flight. [A glitch led to navigation images being marked with the wrong time stamps, which caused Ingenuity to sway back and forth during its flight.] Ingenuity had to power through that and survive and get down on the ground in one piece.

We’ve had some flights that have been dedicated to scouting activities. We went to an area where the rover was going to spend several months, and we went ahead of the rover and scouted [it] out so the rover drivers could be more efficient in finding safe ways to drive. Those were flights 12 and 13. Then some of these longer flights have been exciting. Flight No. 9, until a few days ago, was the biggest thing we’d ever done, at [a distance of] 625 meters. And with flight 25, we just beat that and flew more than 700 meters.

SN: There was a flight recently that had to be postponed because of a dust storm, right?

Grip: That’s correct. That was flight No. 19. With flying, whether it’s on Mars or here on Earth, you’re worried about weather. We always look at the weather before flying. And every time we’ve done that [on Mars], it had been more or less the same. Then the afternoon before we were about to open flight 19, we were notified that we had a dust storm. That delayed us by quite a bit. When we woke up from that, we had dust on our navigation camera lens, and sand covered our legs partially. We had to fly out of that, and it was a new challenge for the helicopter, but again, it tackled that perfectly.

During Ingenuity’s 22nd flight, on March 19, 2022, the helicopter captured a picture of its own shadow on the ground below.JPL-Caltech/NASA

SN: Ingenuity has flown through two seasons on Mars. As seasons change, so does air pressure. Does that affect the helicopter?

Grip: Yeah, that’s a pretty big deal. We knew, for several years before launch, exactly when we were going to land and where we were going to land. Our design was geared towards the first few months after landing, and that coincided with a particular season [spring] in Jezero crater on Mars. We could [ahead of launch] predict reasonably well what the air density would be. And when we extended [the mission] beyond that, the air density started dropping. To be able to keep flying, we had to increase our rotor speed. In fact, we increased it above anything we tested on Earth. Now we’ve come out of summer, the density has started climbing again, and we’ve been able to go back to our original rotor speed and also extend our flight time.

SN: What comes next? Are there any big flights planned soon?

Grip: We’re going to make our way over to the river delta that Perseverance is headed toward. We’ve just completed the biggest obstacle to doing that, flight 25, which was getting across this region called Séítah, which has a lot of sand and varied terrain. And when we get to the river delta, there are a few different options on the table: to help the rover drivers, to scout out targets, or even potentially to do some scouting on behalf of the next Mars mission. Perseverance is the first part of a sample return campaign. It’s sampling right now. And those samples will be left on the surface and will be eventually picked up — that’s the plan anyway — and sent back to Earth.

SN: What does Ingenuity mean for future exploration?

Grip: This is a new era. Aviation in space is now a thing. We can’t think about Mars exploration without aerial assets as part of that. I think that’s the most exciting thing. More

Microtektites found in Caribbean may shed light on tektite origin —Science News, August 11, 1973

Though their origin remains a mystery to scientists, huge strewn fields of tektites have been found in widely separated areas of the world…. Microtektites have now been found in the Caribbean, and the characteristics of these newly found specimens may ultimately shed some light on the question of tektite origin….

Some believe that the tektites come from the moon. They feel that tektites were formed when an asteroid hit the moon, splashing droplets of molten rocks so high that they escaped the moon’s gravity and fell to Earth. However, mass spectrographic analysis of lunar samples shows that elements in the lunar crust are far different from tektites. The tektites are more like the elements in the continental crust of the Earth itself. [Planetary scientist Billy P. Glass] feels that if the parent material of [newfound] microtektites can be determined … the discovery of the origin of the glassy objects might quickly follow suit.

.email-conversion {
border: 1px solid #ffcccb;
color: white;
margin-top: 50px;
background-image: url(“/wp-content/themes/sciencenews/client/src/images/cta-module@2x.jpg”);
padding: 20px;
clear: both;
}

.zephr-registration-form{max-width:440px;margin:20px auto;padding:20px;background-color:#fff;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form *{box-sizing:border-box}.zephr-registration-form-text > *{color:var(–zephr-color-text-main)}.zephr-registration-form-relative-container{position:relative}.zephr-registration-form-flex-container{display:flex}.zephr-registration-form-input.svelte-blfh8x{display:block;width:100%;height:calc(var(–zephr-input-height) * 1px);padding-left:8px;font-size:16px;border:calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-input-borderColor);border-radius:calc(var(–zephr-input-borderRadius) * 1px);transition:border-color 0.25s ease, box-shadow 0.25s ease;outline:0;color:var(–zephr-color-text-main);background-color:#fff;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-input.svelte-blfh8x::placeholder{color:var(–zephr-color-background-tinted)}.zephr-registration-form-input-checkbox.svelte-blfh8x{width:auto;height:auto;margin:8px 5px 0 0;float:left}.zephr-registration-form-input-radio.svelte-blfh8x{position:absolute;opacity:0;cursor:pointer;height:0;width:0}.zephr-registration-form-input-color[type=”color”].svelte-blfh8x{width:50px;padding:0;border-radius:50%}.zephr-registration-form-input-color[type=”color”].svelte-blfh8x::-webkit-color-swatch{border:none;border-radius:50%;padding:0}.zephr-registration-form-input-color[type=”color”].svelte-blfh8x::-webkit-color-swatch-wrapper{border:none;border-radius:50%;padding:0}.zephr-registration-form-input.disabled.svelte-blfh8x,.zephr-registration-form-input.disabled.svelte-blfh8x:hover{border:calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-input-borderColor);background-color:var(–zephr-color-background-tinted)}.zephr-registration-form-input.error.svelte-blfh8x{border:1px solid var(–zephr-color-warning-main)}.zephr-registration-form-input-label.svelte-1ok5fdj.svelte-1ok5fdj{margin-top:10px;display:block;line-height:30px;font-size:12px;color:var(–zephr-color-text-tinted);font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-input-label.svelte-1ok5fdj span.svelte-1ok5fdj{display:block}.zephr-registration-form-button.svelte-17g75t9{height:calc(var(–zephr-button-height) * 1px);line-height:0;padding:0 20px;text-decoration:none;text-transform:capitalize;text-align:center;border-radius:calc(var(–zephr-button-borderRadius) * 1px);font-size:calc(var(–zephr-button-fontSize) * 1px);font-weight:normal;cursor:pointer;border-style:solid;border-width:calc(var(–zephr-button-borderWidth) * 1px);border-color:var(–zephr-color-action-tinted);transition:backdrop-filter 0.2s, background-color 0.2s;margin-top:20px;display:block;width:100%;background-color:var(–zephr-color-action-main);color:#fff;position:relative;overflow:hidden;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-button.svelte-17g75t9:hover{background-color:var(–zephr-color-action-tinted);border-color:var(–zephr-color-action-tinted)}.zephr-registration-form-button.svelte-17g75t9:disabled{background-color:var(–zephr-color-background-tinted);border-color:var(–zephr-color-background-tinted)}.zephr-registration-form-button.svelte-17g75t9:disabled:hover{background-color:var(–zephr-color-background-tinted);border-color:var(–zephr-color-background-tinted)}.zephr-registration-form-text.svelte-i1fi5{font-size:19px;text-align:center;margin:20px auto;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-divider-container.svelte-mk4m8o{display:flex;align-items:center;justify-content:center;margin:40px 0}.zephr-registration-form-divider-line.svelte-mk4m8o{height:1px;width:50%;margin:0 5px;background-color:var(–zephr-color-text-tinted);;}.zephr-registration-form-divider-text.svelte-mk4m8o{margin:0 12px;color:var(–zephr-color-text-main);font-size:14px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);white-space:nowrap}.zephr-registration-form-input-inner-text.svelte-lvlpcn{cursor:pointer;position:absolute;top:50%;transform:translateY(-50%);right:10px;color:var(–zephr-color-text-main);font-size:12px;font-weight:bold;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-response-message.svelte-179421u{text-align:center;padding:10px 30px;border-radius:5px;font-size:15px;margin-top:10px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-response-message-title.svelte-179421u{font-weight:bold;margin-bottom:10px}.zephr-registration-form-response-message-success.svelte-179421u{background-color:#baecbb;border:1px solid #00bc05}.zephr-registration-form-response-message-error.svelte-179421u{background-color:#fcdbec;border:1px solid #d90c00}.zephr-registration-form-social-sign-in.svelte-gp4ky7{align-items:center}.zephr-registration-form-social-sign-in-button.svelte-gp4ky7{height:55px;padding:0 15px;color:#000;background-color:#fff;box-shadow:0px 0px 5px rgba(0, 0, 0, 0.3);border-radius:10px;font-size:17px;display:flex;align-items:center;cursor:pointer;margin-top:20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-social-sign-in-button.svelte-gp4ky7:hover{background-color:#fafafa}.zephr-registration-form-social-sign-in-icon.svelte-gp4ky7{display:flex;justify-content:center;margin-right:30px;width:25px}.zephr-form-link-message.svelte-rt4jae{margin:10px 0 10px 20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-recaptcha-tcs.svelte-1wyy3bx{margin:20px 0 0 0;font-size:15px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-recaptcha-inline.svelte-1wyy3bx{margin:20px 0 0 0}.zephr-registration-form-progress-bar.svelte-8qyhcl{width:100%;border:0;border-radius:20px;margin-top:10px}.zephr-registration-form-progress-bar.svelte-8qyhcl::-webkit-progress-bar{background-color:var(–zephr-color-background-tinted);border:0;border-radius:20px}.zephr-registration-form-progress-bar.svelte-8qyhcl::-webkit-progress-value{background-color:var(–zephr-color-text-tinted);border:0;border-radius:20px}.zephr-registration-progress-bar-step.svelte-8qyhcl{margin:auto;color:var(–zephr-color-text-tinted);font-size:12px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-progress-bar-step.svelte-8qyhcl:first-child{margin-left:0}.zephr-registration-progress-bar-step.svelte-8qyhcl:last-child{margin-right:0}.zephr-registration-form-input-error-text.svelte-19a73pq{color:var(–zephr-color-warning-main);font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-input-select.svelte-19a73pq{display:block;appearance:auto;width:100%;height:calc(var(–zephr-input-height) * 1px);font-size:16px;border:calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-color-text-main);border-radius:calc(var(–zephr-input-borderRadius) * 1px);transition:border-color 0.25s ease, box-shadow 0.25s ease;outline:0;color:var(–zephr-color-text-main);background-color:#fff;padding:10px}.zephr-registration-form-input-select.disabled.svelte-19a73pq{border:1px solid var(–zephr-color-background-tinted)}.zephr-registration-form-input-select.unselected.svelte-19a73pq{color:var(–zephr-color-background-tinted)}.zephr-registration-form-input-select.error.svelte-19a73pq{border-color:var(–zephr-color-warning-main)}.zephr-registration-form-input-textarea.svelte-19a73pq{background-color:#fff;border:1px solid #ddd;color:#222;font-size:14px;font-weight:300;padding:16px;width:100%}.zephr-registration-form-input-slider-output.svelte-19a73pq{margin:13px 0 0 10px}.zephr-registration-form-input-inner-text.svelte-lvlpcn{cursor:pointer;position:absolute;top:50%;transform:translateY(-50%);right:10px;color:var(–zephr-color-text-main);font-size:12px;font-weight:bold;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.spin.svelte-1cj2gr0{animation:svelte-1cj2gr0-spin 2s 0s infinite linear}.pulse.svelte-1cj2gr0{animation:svelte-1cj2gr0-spin 1s infinite steps(8)}@keyframes svelte-1cj2gr0-spin{0%{transform:rotate(0deg)}100%{transform:rotate(360deg)}}.zephr-registration-form-checkbox.svelte-1gzpw2y{position:absolute;opacity:0;cursor:pointer;height:0;width:0}.zephr-registration-form-checkbox-label.svelte-1gzpw2y{display:flex;align-items:center;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-checkmark.svelte-1gzpw2y{position:relative;box-sizing:border-box;height:23px;width:23px;background-color:#fff;border:1px solid var(–zephr-color-text-main);border-radius:6px;margin-right:12px;cursor:pointer}.zephr-registration-form-checkmark.checked.svelte-1gzpw2y{border-color:#009fe3}.zephr-registration-form-checkmark.checked.svelte-1gzpw2y:after{content:””;position:absolute;width:6px;height:13px;border:solid #009fe3;border-width:0 2px 2px 0;transform:rotate(45deg);top:3px;left:8px;box-sizing:border-box}.zephr-registration-form-checkmark.disabled.svelte-1gzpw2y{border:1px solid var(–zephr-color-background-tinted)}.zephr-registration-form-checkmark.disabled.checked.svelte-1gzpw2y:after{border:solid var(–zephr-color-background-tinted);border-width:0 2px 2px 0}.zephr-registration-form-checkmark.error.svelte-1gzpw2y{border:1px solid var(–zephr-color-warning-main)}.zephr-registration-form-input-radio.svelte-1qn5n0t{position:absolute;opacity:0;cursor:pointer;height:0;width:0}.zephr-registration-form-radio-label.svelte-1qn5n0t{display:flex;align-items:center;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-radio-dot.svelte-1qn5n0t{position:relative;box-sizing:border-box;height:23px;width:23px;background-color:#fff;border:1px solid #ebebeb;border-radius:50%;margin-right:12px}.checked.svelte-1qn5n0t{border-color:#009fe3}.checked.svelte-1qn5n0t:after{content:””;position:absolute;width:17px;height:17px;background:#009fe3;background:linear-gradient(#009fe3, #006cb5);border-radius:50%;top:2px;left:2px}.disabled.checked.svelte-1qn5n0t:after{background:var(–zephr-color-background-tinted)}.error.svelte-1qn5n0t{border:1px solid var(–zephr-color-warning-main)}.zephr-form-link.svelte-64wplc{margin:10px 0;color:#6ba5e9;text-decoration:underline;cursor:pointer;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-form-link-disabled.svelte-64wplc{color:var(–zephr-color-text-main);cursor:none;text-decoration:none}.zephr-registration-form-google-icon.svelte-1jnblvg{width:20px}.zephr-registration-form-password-progress.svelte-d1zv9r{display:flex;margin-top:10px}.zephr-registration-form-password-bar.svelte-d1zv9r{width:100%;height:4px;border-radius:2px}.zephr-registration-form-password-bar.svelte-d1zv9r:not(:first-child){margin-left:8px}.zephr-registration-form-password-requirements.svelte-d1zv9r{margin:20px 0;justify-content:center}.zephr-registration-form-password-requirement.svelte-d1zv9r{display:flex;align-items:center;color:var(–zephr-color-text-tinted);font-size:12px;height:20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-password-requirement-icon.svelte-d1zv9r{margin-right:10px;font-size:15px}.zephr-registration-form-password-progress.svelte-d1zv9r{display:flex;margin-top:10px}.zephr-registration-form-password-bar.svelte-d1zv9r{width:100%;height:4px;border-radius:2px}.zephr-registration-form-password-bar.svelte-d1zv9r:not(:first-child){margin-left:8px}.zephr-registration-form-password-requirements.svelte-d1zv9r{margin:20px 0;justify-content:center}.zephr-registration-form-password-requirement.svelte-d1zv9r{display:flex;align-items:center;color:var(–zephr-color-text-tinted);font-size:12px;height:20px;font-family:var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont)}.zephr-registration-form-password-requirement-icon.svelte-d1zv9r{margin-right:10px;font-size:15px}
.zephr-registration-form {
max-width: 100%;
background-image: url(https://www.sciencenews.org/wp-content/uploads/2023/05/newsletter-signup-background_REV.jpg);
background-position: top 75% left 67%;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
margin: 0px auto;
margin-bottom: 4rem;
padding: 20px;
}

.zephr-registration-form-text.svelte-i1fi5 p {
padding-left: 10px;
padding-right: 10px;
padding-bottom: 10px;
}

.zephr-registration-form-text.svelte-i1fi5 h2 {
padding-top: 10px;
}

.zephr-registration-form-text h6 {
font-size: 0.8rem;
}

.zephr-registration-form h4 {
font-size: 3rem;
}

.zephr-registration-form h4 {
font-size: 1.5rem;
}

.zephr-registration-form-button.svelte-17g75t9:hover {
background-color: #fc6a65;
border-color: #fc6a65;
width: 150px;
margin-left: auto;
margin-right: auto;
}
.zephr-registration-form-button.svelte-17g75t9:disabled {
background-color: #e04821;
border-color: #e04821;
width: 150px;
margin-left: auto;
margin-right: auto;
}
.zephr-registration-form-button.svelte-17g75t9 {
background-color: #e04821;
border-color: #e04821;
width: 150px;
margin-left: auto;
margin-right: auto;
}
.zephr-registration-form-text > * {
color: #FFFFFF;
font-weight: bold
font: 25px;
background-color: rgba(10,10,10,0.7)
}
.zephr-registration-form-progress-bar.svelte-8qyhcl {
width: 100%;
border: 0;
border-radius: 20px;
margin-top: 10px;
display: none;
}
.zephr-registration-form-response-message-title.svelte-179421u {
font-weight: bold;
margin-bottom: 10px;
display: none;
}
.zephr-registration-form-response-message-success.svelte-179421u {
background-color: #8db869;
border: 1px solid #8db869;
color: white;
margin-top: -0.2rem;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(1){
font-size: 18px;
text-align: center;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(5){
font-size: 18px;
text-align: left;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(7){
font-size: 18px;
text-align: left;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-text.svelte-i1fi5:nth-child(9){
font-size: 18px;
text-align: left;
margin: 20px auto;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
}
.zephr-registration-form-input-label.svelte-1ok5fdj span.svelte-1ok5fdj {
display: none;
color: white;
}
.zephr-registration-form-input.disabled.svelte-blfh8x, .zephr-registration-form-input.disabled.svelte-blfh8x:hover {
border: calc(var(–zephr-input-borderWidth) * 1px) solid var(–zephr-input-borderColor);
background-color: white;
}
.zephr-registration-form-checkbox-label.svelte-1gzpw2y {
display: flex;
align-items: center;
font-family: var(–zephr-typography-body-font), var(–zephr-typography-body-fallbackFont);
color: white;
font-size: 20px;
margin-bottom: -20px;
}
.zephr-registration-progress-bar-step.svelte-8qyhcl:first-child {
display: none;
}
.zephr-registration-progress-bar-step.svelte-8qyhcl:last-child {
display: none;
}

Update

Glass surmised that these geologic curiosities have earthly origins, based on his and his colleagues’ analyses of the North American strewn field — a blanket of glassy particles that covers much the southeastern United States and Caribbean and dates to about 35 million years ago. But it took another 20 years for researchers to identify the source.

In 1994, tektites and concentric fault lines in southern Virginia revealed an 85-kilometer-wide impact crater under Chesapeake Bay. Science News reported that “a structure this size would rank as the largest crater in the United States” and would be among the largest on Earth (SN: 8/20/94). What’s more, when the space rock slammed into our planet, the collision created intense seismic waves that bent microfossils into odd shapes, scientists reported nearly a decade later (SN: 6/11/03). 

Taken together with evidence from Earth’s three other major strewn fields, the findings helped confirm that tektites form when a bolide slams into our planet with enough force to blast liquified chunks of Earth’s crust into the atmosphere. These chunks then harden into raindrop-, barbell- and ravioli-shaped particles as they fall back to the surface.

So far, researchers have linked three of the four major strewn fields with impact craters. The North American strewn field is tied to the Chesapeake crater in Virginia, the central European strewn field is associated with the Ries crater in Germany, and the Ivory Coast strewn field originates from the Bosumtwi crater in Ghana. The holdout is the Australasian strewn field, which is the largest known and covers about 10 percent of Earth’s surface.

Tektites are strong indicators of bolide impacts, but researchers also consider other geologic evidence. In this light micrograph, quartz crystals recovered about 20 kilometers southeast of the proposed location of the Australasian crater display fractures consistent with an impact. Courtesy of Dayana Schonwalder Angel

Scientists recently got a break in the case. Analyses of tektites found in Thailand and other geologic evidence as well as computer simulations suggest a probable source. A 2-kilometer-wide meteorite struck Laos about 800,000 years ago and flung debris across Asia, Australia and Antarctica, scientists reported in 2020 in the Proceedings of the National Academy of Sciences.

The resulting crater, which may be about 13 kilometers wide by 17 kilometers long, was eventually buried under volcanic material, the team contends. Verifying this hypothesis will require drilling through lava fields to see if the rocks underneath show melting and shattering — both hallmarks of an impact.

To a collector, the curiosities found around an impact crater are full of wonder and poetry. To a planetary scientist, these small pieces of evidence may yet open big windows into Earth’s geologic past. More

As our planet orbits the sun, it swoops through clouds of extraterrestrial dust — and several thousand metric tons of that material actually reaches Earth’s surface every year, new research suggests.

During three summers in Antarctica over the past two decades, researchers collected more than 2,000 micrometeorites from three snow pits that they’d dug. Extrapolating from this meager sample to the rest of the world, tiny pebbles from space account for a whopping 5,200 metric tons of weight gain each year, researchers report in the April 15 Earth and Planetary Science Letters.

Much of Antarctica is the perfect repository for micrometeorites because there’s no liquid water to dissolve or otherwise destroy them, says Jean Duprat, a cosmochemist at Sorbonne University in Paris (SN: 5/29/20). Nevertheless, collecting the samples was no easy chore.

First, Duprat and colleagues had to dig down two meters or more to reach layers of snow deposited before 1995, the year when researchers set up a field station at an inland site dubbed Dome C. Then they used ultraclean tools to collect hundreds of kilograms of snow, melt it and sieve the tiny treasures from the frigid water.

To hunt for micrometeorites that have fallen to Antarctica in recent decades, researchers dig trenches (pictured) to collect snow that is later melted and then sieved for the space dust.J. Duprat, C. Engrand, CNRS Photothèque

In all, the team found 808 spherules that had partially melted as they blazed through Earth’s atmosphere and another 1,280 micrometeorites that showed no such damage. The particles ranged in size from 30 to 350 micrometers across and all together weigh mere fractions of a gram. But the micrometeorites were all found within three areas totaling just a few square meters, the merest fraction of Earth’s surface. Assuming that particles of space dust are just as likely to fall in Antarctica as anywhere else let the team estimate how much dust fell over the entire planet.

The team’s findings “are a wonderful complement to previous studies,” says Susan Taylor, a geologist at the Cold Regions Research and Engineering Laboratory in Hanover, N.H., who was not involved in the new study. That’s because Duprat and colleagues found a lot of the small stuff that would have dissolved elsewhere, she notes.

About 80 percent of the micrometeorites originate from comets that spend much of their orbits closer to the sun than Jupiter, the researchers estimate. Much of the rest probably derive from collisions of objects in the asteroid belt. All together, these tiny particles deliver somewhere between 20 and 100 metric tons of carbon to Earth each year, Duprat and colleagues suggest, and could have been an important source of carbon-rich compounds such as amino acids early in Earth’s history (SN: 12/4/20). More

A new study casts a haze over a hint of the universe’s first glimmers of starlight.

In 2018, researchers claimed that a subtle signature in radio waves from early in the universe’s history had revealed the era when the first stars switched on, known as the cosmic dawn. But the first experiment to test that study’s conclusions found no sign of those early stars, scientists report February 28 in Nature Astronomy.

Just after the Big Bang about 13.8 billion years ago, the universe was a hot stew of matter. Stars probably didn’t flicker on until at least 100 million years later — a poorly understood era of the cosmos. Finding signs of the first beams of starlight would flesh out the cosmic origin story. So the 2018 claim of pinpointing those earliest gleams, from the EDGES experiment in the Australian outback, caused an astronomical hubbub (SN: 2/28/18).

Sign Up For the Latest from Science News

Headlines and summaries of the latest Science News articles, delivered to your inbox

Thank you for signing up!

There was a problem signing you up.

“It definitely completely excited our whole community with this fascinating result,” says radio astronomer Saurabh Singh of the Raman Research Institute in Bangalore, India.

The researchers reported detecting a dip across particular wavelengths of radio waves, a sign of light from the first stars interacting with surrounding hydrogen gas. But the result quickly raised skepticism, because the dip was deeper than expected. To know whether the hint of the first starlight was real, scientists would need to make more measurements.

Singh and colleagues did just that with the Shaped Antenna Measurement of the Background Radio Spectrum 3, or SARAS 3. Similar to EDGES, the experiment uses an antenna to pick up radio waves. But SARAS 3 has a different design from EDGES, with a differently shaped antenna. And SARAS 3 is designed to float atop a lake. “That gives us a very distinctive advantage,” Singh says.

On Earth, radio waves come from a variety of sources, which must be carefully accounted for to reveal the subtler signal from the cosmic dawn. Misunderstanding those other sources of radio waves could lead to an unaccounted-for experimental error that might give incorrect results.

In particular, experiments on land must contend with radio waves emitted from the ground, which are difficult to estimate due to the complex, layered nature of soil. When the antenna is atop a lake, it’s easier to estimate what kinds of radio waves come from the uniform water below. Data taken from two lakes in India revealed no sign of the dip.

The new study “highlights just how difficult this measurement is,” says physicist H. Cynthia Chiang of McGill University in Montreal. It’s uncomfortable that the two studies disagree, she says, but notes that the disagreement “isn’t quite enough to make any definitive conclusions at this point.”

And some of the same types of experimental issues that may affect EDGES could also affect SARAS 3, says experimental cosmologist Judd Bowman of Arizona State University in Tempe, a member of the EDGES team. “We still have more work ahead to reach the final outcome.”

An improved version of EDGES will be deployed later this year, and the SARAS 3 team has additional deployments planned. Other experiments are also working on similar measurements. Those tests may finally illuminate the universe’s transition from darkness to light. More

Earth’s deep stores of water may have been locally sourced rather than trucked in from far-flung regions of the solar system.
A new analysis of meteorites from the inner solar system — home to the four rocky planets — suggests that Earth’s building blocks delivered enough water to account for all the H2O buried within the planet. What’s more, the water produced by the local primordial building material likely shares a close chemical kinship with Earth’s deep-water reserves, thus strengthening the connection, researchers report in the Aug. 28 Science.
Earth is thought to have been born in an interplanetary desert, too close to the sun for water ice to survive. Many researchers suspect that ocean water got delivered toward the end of Earth’s formation by ice-laden asteroids that wandered in from cooler, more distant regions of the solar system (SN: 5/6/15). But the ocean isn’t the planet’s largest water reservoir. Researchers estimate that Earth’s interior holds several times as much water as is found at the surface.
To test whether or not the material that formed Earth could have delivered this deep water, cosmochemist Laurette Piani of the University of Lorraine in Vandœuvre-lès-Nancy, France, and colleagues analyzed meteorites known as enstatite chondrites. Thanks to many chemical similarities with Earth rocks, these relatively rare meteorites are widely thought to be good analogs of the dust and space rocks from the inner solar system that formed Earth’s building blocks, Piani says.

Sign Up For the Latest from Science News

Headlines and summaries of the latest Science News articles, delivered to your inbox

She and her team measured the abundance of hydrogen in these meteorites — a proxy for how much H2O they could produce — and calculated that local interplanetary debris had the potential to deliver at least three times as much water as is found in all the oceans. The meteorites don’t contain water, Piani says. Rather, they house enough of the raw ingredients to create water when heated.
In the meteorites, the team also found a close match to the type of water found in Earth’s mantle. A smattering of all water molecules on Earth contain a heavy variant of hydrogen known as deuterium. The ratio of deuterium to hydrogen in the enstatite chondrites lies within the range measured in Earth’s deep water. That similarity, the team argues, makes a strong case for local building blocks being the source of much of the planet’s water.
“This work is something I wanted to do myself or had been waiting for someone to do,” says Lydia Hallis, a planetary scientist at the University of Glasgow in Scotland. In 2015, she led a team that measured the deuterium abundance in lava plumes that tap deep into Earth’s mantle (SN: 11/12/15). “I’m really happy that [the new data] sits within the region where our previous data from deep mantle samples is sitting.”
Hallis and others stress that these new measurements are difficult. Once the meteorites hit the ground, they quickly absorb hydrogen from Earth’s environment. “They did a really good job of picking the right meteorites and making the right measurements,” she says. “This is pretty convincing that this hydrogen that’s measured is from the enstatite chondrites rather than from terrestrial contamination.”
The enstatite chondrites could have also contributed a lot of water to the oceans as well — but they are not the full story. The deuterium-hydrogen ratio in ocean water, which is a bit higher than that of mantle water, is better matched to the ratio found in icy asteroids from the outer solar system. “We still need a bit of water coming from the outer solar system,” Piani says. So, while local materials may have delivered the bulk of Earth’s water, the oceans were likely topped off a bit later by collisions with remote space rocks. More