<div data-thumb=”https://scx1.b-cdn.net/csz/news/tmb/2022/a-close-encounter-with.jpg” data-src=”https://scx2.b-cdn.net/gfx/news/hires/2022/a-close-encounter-with.jpg” data-sub-html=”The High Resolution Stereo Camera (HRSC) onboard the ESA spacecraft Mars Express took this image of Phobos using the HRSC nadir channel on 7 March 2010, HRSC Orbit 7915. This image has additionally been enhanced photometrically for better bringing features in the less illuminated part. Resolution: about 4.4 meters per pixel. Credit: ESA/DLR/FU Berlin (G. Neukum), CC BY-SA 3.0 IGO“>
<img src=”https://scx1.b-cdn.net/csz/news/800a/2022/a-close-encounter-with.jpg” alt=”A close encounter with a mysterious moon” title=”The High Resolution Stereo Camera (HRSC) onboard the ESA spacecraft Mars Express took this image of Phobos using the HRSC nadir channel on 7 March 2010, HRSC Orbit 7915. This image has additionally been enhanced photometrically for better bringing features in the less illuminated part. Resolution: about 4.4 meters per pixel. Credit: ESA/DLR/FU Berlin (G. Neukum), CC BY-SA 3.0 IGO” width=”800″ height=”530″>The High Resolution Stereo Camera (HRSC) onboard the ESA spacecraft Mars Express took this image of Phobos using the HRSC nadir channel on 7 March 2010, HRSC Orbit 7915. This image has additionally been enhanced photometrically for better bringing features in the less illuminated part. Resolution: about 4.4 meters per pixel. Credit: ESA/DLR/FU Berlin (G. Neukum), CC BY-SA 3.0 IGO
In 1877, American astronomer Asaph Hall discovered two small moons circling the planet Mars, later named Phobos and Deimos after the Greek for “fear” and “panic.”
But it was excitement, rather than fear and panic, that characterized the close encounter with Phobos made by ESA’s Mars Express spacecraft in the run up to Halloween this year. The recent flyby of the larger Martian moon offered the perfect opportunity to test one of the 19-year-old spacecraft’s latest upgrades.
The MARSIS instrument on Mars Express was originally designed to study the internal structure of Mars. As a result, it was designed for use at the typical distance between the spacecraft and the planet’s surface—more than 250 km.
But it recently received a major software upgrade that allows it to be used at much closer distances and which could help to shed light on the mysterious origin of the moon Phobos.
“During this flyby, we used MARSIS to study Phobos from as close as 83 km,” says Andrea Cicchetti from the MARSIS team at INAF. “Getting closer allows us to study its structure in more detail and identify important features we would never have been able to see from further away. In future, we are confident we could use MARSIS from closer than 40 km. The orbit of Mars Express has been fine-tuned to get us as close to Phobos as possible during a handful of flybys between 2023 and 2025, which will give us great opportunities to try.”
“We didn’t know if this was possible,” says Simon Wood, Mars Express flight controller at ESA’s ESOC operations center, who oversaw the upload of the new software to the ESA spacecraft. “The team tested a few different variations of the software, with the final, successful tweaks uploaded to the spacecraft just hours before the flyby.”
Artist’s impression of water under the martian surface. If underground aquifers like that really do exist, Mars Express has a good chance of finding them. The implications for human exploration and eventual colonisation of the red planet would be far-reaching. Credit: Medialab, ESA 2001
Mysterious origins
MARSIS, famous for its role in the discovery of signs of liquid water on the Red Planet, sends low-frequency radio waves towards Mars or Phobos, using its 40-meter long antenna.
Most of these waves are reflected from the body’s surface, but some travel through and are reflected at boundaries between layers of different materials below the surface.
By examining the reflected signals, scientists can map the structure below the surface and study properties such as the thickness and composition of the material.
For Mars, this could reveal different layers of ice, soil, rock or water. But the internal structure of Phobos is more of a mystery, and the upgrade to MARSIS could offer important insight.
“Whether Mars’ two small moons are captured asteroids or made of material ripped from Mars during a collision is an open question,” says ESA Mars Express scientist Colin Wilson. “Their appearance suggests they were asteroids, but the way they orbit Mars arguably suggests otherwise.”
“We are still at an early stage in our analysis,” says Andrea. “But we have already seen possible signs of previously unknown features below the moon’s surface. We are excited to see the role that MARSIS might play in finally solving the mystery surrounding Phobos’ origin.”
The MARSIS instrument on ESA’s Mars Express spacecraft uses its recently upgraded software to peer beneath the surface of the martian moon Phobos. Credit: INAF – Istituto Nazionale di Astrofisica
What does this image show?
The top-right image shows the “radargram” acquired by MARSIS during the flyby of Phobos on 23 September 2022. A radargram reveals the “echoes” created when the radio signal emitted by MARSIS bounces off something and returns to the instrument. The brighter the signal, the more powerful the echo.
The continuous bright line shows the echo from the moon’s surface. The lower reflections are either “clutter” caused by features on the moon’s surface, or, more interestingly, signs of possible structural features below the surface (e).
“Section A–C was recorded using an older configuration of the MARSIS software,” says Carlo Nenna, MARSIS on-board software engineer at Enginium, who is implementing the upgrade. “The new configuration was prepared during the ‘technical gap’ and successfully used for the very first time from D–F.”
The left and bottom-right images show the path of the observation across the surface of Phobos.
Citation:
A close encounter with a mysterious moon (2022, October 31)
retrieved 31 October 2022
from https://phys.org/news/2022-10-encounter-mysterious-moon.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
The European Space Agency is fast-tracking a new mission called Ramses, which will fly to near-Earth asteroid 99942 Apophis and join the space rock in 2029 when it comes very close to our planet — closer even than the region where geosynchronous satellites sit.
Ramses is short for Rapid Apophis Mission for Space Safety and, as its name suggests, is the next phase in humanity’s efforts to learn more about near-Earth asteroids (NEOs) and how we might deflect them should one ever be discovered on a collision course with planet Earth.
In order to launch in time to rendezvous with Apophis in February 2029, scientists at the European Space Agency have been given permission to start planning Ramses even before the multinational space agency officially adopts the mission. The sanctioning and appropriation of funding for the Ramses mission will hopefully take place at ESA’s Ministerial Council meeting (involving representatives from each of ESA’s member states) in November of 2025. To arrive at Apophis in February 2029, launch would have to take place in April 2028, the agency says.
This is a big deal because large asteroids don’t come this close to Earth very often. It is thus scientifically precious that, on April 13, 2029, Apophis will pass within 19,794 miles (31,860 kilometers) of Earth. For comparison, geosynchronous orbit is 22,236 miles (35,786 km) above Earth’s surface. Such close fly-bys by asteroids hundreds of meters across (Apophis is about 1,230 feet, or 375 meters, across) only occur on average once every 5,000 to 10,000 years. Miss this one, and we’ve got a long time to wait for the next.
When Apophis was discovered in 2004, it was for a short time the most dangerous asteroid known, being classified as having the potential to impact with Earth possibly in 2029, 2036, or 2068. Should an asteroid of its size strike Earth, it could gouge out a crater several kilometers across and devastate a country with shock waves, flash heating and earth tremors. If it crashed down in the ocean, it could send a towering tsunami to devastate coastlines in multiple countries.
Over time, as our knowledge of Apophis’ orbit became more refined, however, the risk of impact greatly went down. Radar observations of the asteroid in March of 2021 reduced the uncertainty in Apophis’ orbit from hundreds of kilometers to just a few kilometers, finally removing any lingering worries about an impact — at least for the next 100 years. (Beyond 100 years, asteroid orbits can become too unpredictable to plot with any accuracy, but there’s currently no suggestion that an impact will occur after 100 years.) So, Earth is expected to be perfectly safe in 2029 when Apophis comes through. Still, scientists want to see how Apophis responds by coming so close to Earth and entering our planet’s gravitational field.
Breaking space news, the latest updates on rocket launches, skywatching events and more!
“There is still so much we have yet to learn about asteroids but, until now, we have had to travel deep into the solar system to study them and perform experiments ourselves to interact with their surface,” said Patrick Michel, who is the Director of Research at CNRS at Observatoire de la Côte d’Azur in Nice, France, in a statement. “Nature is bringing one to us and conducting the experiment itself. All we need to do is watch as Apophis is stretched and squeezed by strong tidal forces that may trigger landslides and other disturbances and reveal new material from beneath the surface.”
The Goldstone radar’s imagery of asteroid 99942 Apophis as it made its closest approach to Earth, in March 2021. (Image credit: NASA/JPL–Caltech/NSF/AUI/GBO)
By arriving at Apophis before the asteroid’s close encounter with Earth, and sticking with it throughout the flyby and beyond, Ramses will be in prime position to conduct before-and-after surveys to see how Apophis reacts to Earth. By looking for disturbances Earth’s gravitational tidal forces trigger on the asteroid’s surface, Ramses will be able to learn about Apophis’ internal structure, density, porosity and composition, all of which are characteristics that we would need to first understand before considering how best to deflect a similar asteroid were one ever found to be on a collision course with our world.
Besides assisting in protecting Earth, learning about Apophis will give scientists further insights into how similar asteroids formed in the early solar system, and, in the process, how planets (including Earth) formed out of the same material.
One way we already know Earth will affect Apophis is by changing its orbit. Currently, Apophis is categorized as an Aten-type asteroid, which is what we call the class of near-Earth objects that have a shorter orbit around the sun than Earth does. Apophis currently gets as far as 0.92 astronomical units (137.6 million km, or 85.5 million miles) from the sun. However, our planet will give Apophis a gravitational nudge that will enlarge its orbit to 1.1 astronomical units (164.6 million km, or 102 million miles), such that its orbital period becomes longer than Earth’s.
It will then be classed as an Apollo-type asteroid.
Ramses won’t be alone in tracking Apophis. NASA has repurposed their OSIRIS-REx mission, which returned a sample from another near-Earth asteroid, 101955 Bennu, in 2023. However, the spacecraft, renamed OSIRIS-APEX (Apophis Explorer), won’t arrive at the asteroid until April 23, 2029, ten days after the close encounter with Earth. OSIRIS-APEX will initially perform a flyby of Apophis at a distance of about 2,500 miles (4,000 km) from the object, then return in June that year to settle into orbit around Apophis for an 18-month mission.
Related Stories:
Furthermore, the European Space Agency still plans on launching its Hera spacecraft in October 2024 to follow-up on the DART mission to the double asteroid Didymos and Dimorphos. DART impacted the latter in a test of kinetic impactor capabilities for potentially changing a hazardous asteroid’s orbit around our planet. Hera will survey the binary asteroid system and observe the crater made by DART’s sacrifice to gain a better understanding of Dimorphos’ structure and composition post-impact, so that we can place the results in context.
The more near-Earth asteroids like Dimorphos and Apophis that we study, the greater that context becomes. Perhaps, one day, the understanding that we have gained from these missions will indeed save our planet.
