MASS

 

Blog for Sunday, June 25, 2023

It’s been a relatively slow week of news, but here are a couple of items I learned about recently.

OSIRIS-REx Sample Return -- In the June Planetary Society publication, they had a feature article about the return of the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security- Regolith Explorer) probe with its sample of the asteroid Bennu. It’s been almost 7 years since it was launched on September 8, 2016 to the .5 km diameter carbonaceous asteroid. Scientists think the ancient surface of Bennu might have formed only 10 million years after the Sun making it about 4.5 billion years ago.

The rubble-pile asteroid surprised scientists with its rocky surface and the probe circled Bennu for 505 days before deciding where to take its sample. During the sampling process, people were stunned that the sample arm plunged 2 feet into the surface and created a flurry of dust, rocks and pebbles. Dante Lauretta, chief scientist, feels they might have gotten a 250-gram (a baseball’s mass) sample, far exceeding the 59.5-gram goal.

On Sunday, September 24, 2023, the sample return capsule will detach from the main probe, 4 hours and 60,000 miles away from Earth and then plunge into the atmosphere at a blistering 7.7 miles per second. Protected with a heat shield, the capsule will slow for 2 minutes before deploying its parachute and descending from 3200 ft to a 12 by 50-mile target ellipse in the Utah Test Range. With this heat shield protection, scientists will be able to analyze the material of the asteroid without it undergoing the heat and pressure that a meteor sample would endure.

The asteroid Bennu is known as a Potentially Hazardous Object (PHO) because its 1.2-year orbit brings it within 186,000 miles of Earth every 6 years. Astronomers calculate that it has a 1 in 1800 chance of colliding with Earth between 2178 and 2290. That’s a long shot, but the downside is it would take out an entire continent if it did hit us. The more we understand these objects, the better chance we have of doing something about it when there is a danger of collision.

Euclid Space Telescope to Launch – Euclid is scheduled to launch on a Falcon 9 rocket from Florida on Saturday, July 1. It will travel for 30 days to the L2 point beyond the moon just like the JWST. But Euclid will be a survey telescope meaning it won’t study individual objects. Over 6 years, it will survey 1/3 of the sky avoiding the plane of the Milky Way and the plane of the Solar System where dust would inhibit its observations. It will map galaxies out to 10 billion light-years away. Using spectroscopy, it will be able to estimate the distance to galaxies and create a 3-D map of the universe. It has 3 major goals: 1) how do galaxies change over time? 2) create a dark matter map by analyzing the distortion of galaxy shapes in its images; and 3) how does the expansion rate of the universe change over time? The first release of data will be 2.5 years after launch. All the mission’s questions are one of intense interest to me, so I can’t wait until 2026 for this first set of data.