massachusetts institute of technology Archives

September 15, 2024September 15, 2024 by Matt Williams

Early Dark Energy Could Resolve Two of the Biggest Mysteries in Cosmology

This is a small portion of the field observed by NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) for the Cosmic Evolution Early Release Science (CEERS) survey. It is filled with galaxies. The light from some of them has traveled for over 13 billion years to reach the telescope. Credit: NASA, ESA, CSA, Steve Finkelstein (University of Texas at Austin)

Of all the mysteries facing astronomers and cosmologists today, the “Hubble Tension” remains persistent! This term refers to the apparent inconsistency of the Universe’s expansion (aka. the Hubble Constant) when local measurements are compared to those of the Cosmic Microwave Background (CMB). Astronomers hoped that observations of the earliest galaxies in the Universe by the James Webb Space Telescope (JWST) would solve this mystery. Unfortunately, Webb confirmed that the previous measurements were correct, so the “tension” endures.

Since the JWST made its observations, numerous scientists have suggested that the existence of Early Dark Energy (EDE) might explain the Hubble Tension. In a recent study supported by NASA and the National Science Foundation (NSF), researchers from the Massachusetts Institute of Technology (MIT) suggested that EDE could resolve two cosmological mysteries. In addition to the Hubble Tension, it might explain why Webb observed as many galaxies as it did during the early Universe. According to current cosmological models, the Universe should have been much less populated at the time.

January 5, 2023January 8, 2023 by Laurence Tognetti

What Does it Take to Make Black Holes Collide?

Simulation of the emitted light from a supermassive black hole binary system. (Credit: NASA’s Goddard Space Flight Center)

In a recent study published in Astronomy and Astrophysical Letters, a team of researchers at the Massachusetts Institute of Technology (MIT) used various computer models to examine 69 confirmed binary black holes to help determine their origin, and found their data results changed based on the model’s configurations, and the researchers wish to better understand both how and why this occurs and what steps can be taken to have more consistent results.

April 2, 2021April 2, 2021 by Matt Williams

If Astronomers see Isoprene in the Atmosphere of an Alien World, There’s a Good Chance There’s Life There

Artists’s impression of the rocky super-Earth HD 85512 b. Credit: ESO/M. Kornmesser

It is no exaggeration to say that the study of extrasolar planets has exploded in recent decades. To date, 4,375 exoplanets have been confirmed in 3,247 systems, with another 5,856 candidates awaiting confirmation. In recent years, exoplanet studies have started to transition from the process of discovery to one of characterization. This process is expected to accelerate once next-generation telescopes become operational.

As a result, astrobiologists are working to create comprehensive lists of potential “biosignatures,” which refers to chemical compounds and processes that are associated with life (oxygen, carbon dioxide, water, etc.) But according to new research by a team from the Massachusetts Institute of Technology (MIT), another potential biosignature we should be on the lookout for is a hydrocarbon called isoprene (C₅H₈).

November 20, 2013December 23, 2015 by Elizabeth Howell

Asteroids Can Get Shaken And Stirred By Mars’ Gravity

Artist's conception of Mars, with asteroids nearby. Credit: NASA

Asteroids are sometimes called loose rubble piles, which leads to interesting effects if they happen to get close to a planet. A science team in 2010 found out that when asteroids get close to Earth, the gravity of our planet can stir up the dust grains and “refresh” its face, in a sense. Now, scientists have found that Mars can do the same thing.

Here’s the interesting part: the asteroid belt is in between Mars and Jupiter, which means that potentially more asteroids could be changed from the influence of Mars than what happens near Earth.

“Mars is right next to the asteroid belt, and in a way it gets more opportunity than the Earth does to refresh asteroids,” stated Richard Binzel, a professor of planetary sciences at the Massachusetts Institute of Technology who participated in both sets of research.

Artist’s impression of the asteroid (234) Barbara. Thanks to a unique method that uses ESO’s Very Large Telescope Interferometer, astronomers have been able to measure sizes of small asteroids in the main belt for the first time. Their observations also suggest that Barbara has a complex concave shape, best modelled as two bodies that may possibly be in contact. Credit: ESO/L. Calçada

“Picture Mars and an asteroid going through an intersection, and sometimes they’ll both come through at very nearly the same time,” Binzel added. “If they just barely miss each other, that’s close enough for Mars’ gravity to tug on [the asteroid] and shake it up. It ends up being this random process as to how these things happen, and how often.”

The initial research in 2010 showed that most asteroids are redder than meteorites. On asteroids, the surfaces get exposed to cosmic radiation and become redder as time goes on. But when as asteroid gets close to Earth, the planet’s gravity moves around the surface particles and brings fresher bits from underneath. Meteorites that break off from these asteroids would therefore not be as red.

This time around, Binzel’s team looked at other possibilities to “refresh” asteroids, such as collisions or energy from the sun, but concluded that the planets are probably the big reason we see the changed surfaces. You can read more details on the research in the journal Icarus or the preprint version on Arxiv. The lead author on the article was MIT planetary scientist Francesca DeMeo.

Source: MIT