Space News & Blog Articles

For decades, scientists engaged in the search for life in the Universe (aka. astrobiology) have focused on searching for life on other Earth-like planets. These included terrestrial (aka. rocky) planets beyond our Solar System (extrasolar planets) and ones here at home. Beyond Earth, Mars is considered to be the most habitable planet next to Earth, and scientists have also theorized that life could exist (in microbial form) in the cloud tops of Venus.

In all cases, a major focal point is whether or not planets have large bodies of water on their surfaces (or did in the past). However, a new study led by a research team from the UK and German (with support from NASA) has shown that the existence of life may have less to do with the quantity of water and more to with the presence of atmospheric water molecules. As a result, we may have better luck finding life on Jupiter’s turbulent cloud deck than Venus’.

The study that describes their findings, which was recently published in Nature Astronomy under the title “Water activity in Venus’s uninhabitable clouds and other planetary atmospheres,” was led by Dr. John E. Hallsworth of the School of Biological Sciences at Queen’s University Belfast. He was joined by colleagues from multiple universities in the UK and Germany, and the NASA Ames Research Center’s Space Science Division (SSD).

Venus has been the focal point of a lot of interest lately, ever since the announcement that phosphine gas had been detected in the planet’s dense atmosphere. These findings, according to a team of independent researchers, was a possible sign that microbial life might exist in Venus’ sulfuric acid clouds (aka. a potential biosignature). However, according to this latest study, Venus’ atmosphere doesn’t have enough water activity to support this claim.

This conclusion is based on a new method devised by Hallsworth and his colleagues to determine the leve of water activity in a planet’s atmospheres. They then applied this method on Venus’ atmosphere, where temperatures range from 30 to 80 °C (86 to 176 °F) at altitudes of 50 km (30 mi) above the surface and water vapor accounts for about 0.002% of the atmosphere by volume.

Aim for the Center

The Milky Way is 13 BILLION years old. Some of our Galaxy’s oldest stars were born near the beginning of the Universe itself. During all these eons of time, we know at least one technological civilization has been born – US!

But if the Galaxy is so ancient, and we know it can create life, why haven’t we heard from anybody else? If another civilization was just 0.1% of the Galaxy’s age older than we are, they would be millions of years further along than us and presumably more advanced. If we are already on the cusp of sending life to other worlds, shouldn’t the Milky Way be teeming with alien ships and colonies by now?

Maybe. But it’s also possible that we’ve been looking in the wrong place. Recent computer simulations by Jason T. Wright et al suggest that the best place to look for ancient space-faring civilizations might be the core of the Galaxy, a relatively unexplored target in the search for extra terrestrial intelligence.

The Churn

Older mathematical models of space colonization have tried to determine the time required for a civilization to spread throughout the Milky Way. Given the size of the Milky Way, wide-scale galactic colonization could take longer than the age of the Galaxy itself. However, a unique feature of this new simulation is its accounting for the motion of the Galaxy’s stars. The Milky Way is not static, as assumed in prior models, rather it is a churning swirling mass. Colonization vessels or probes would be flying among stars that are themselves in motion. The new simulation reveals that stellar motion aids in colonization contributing a diffusing effect to the spread of a civilization.

The simulation is based previous research by Jonathan Carroll-Nellenback et al which proposed that a hypothetical civilization could spread at sub-light speeds through a moving Galaxy. The simulation assumes a civilization using ships travelling at velocities comparable to our own spacecraft (about 30km/s). When a ship arrives at a virtual habitable world in the simulation, the world is considered a colony and can itself launch another craft every 100,000 years if another uninhabited world is in range. Simulated space craft range is 10 light years with maximum travel duration of 300,000 years. Technology from a virtual colony was set to last 100 million years before dying out with the opportunity to be resettled should another colony drift into range by galactic motion.

Things are not looking very good for the Hubble Space Telescope right now. On Sunday, June 13th, the telescope’s payload computer suddenly stopped working, prompting the main computer to put the telescope into safe mode. While the telescope itself and its science instruments remain in working order, science operations have been suspended until the operations team can figure out how to get the payload computer back online.

While attempting to restart the computer, the operations team has also tried to trace the issue to specific components in the payload computer and switch to their backup modules. As of June 30th, the team began looking into the Command Unit/Science Data Formatter (CU/SDF) and the Power Control Unit (PCU). Meanwhile, NASA is busy preparing and testing procedures to switch to backup hardware if either of these components are the culprit.

The payload computer is part of the Science Instrument Command and Data Handling (SI C&DH) unit, where it is responsible for controlling and coordinating the scientific instruments aboard the spacecraft. The current issues began when the main computer stopped receiving the “keep-alive” signal from the payload computer – which lets the main computer know that everything is working.

That’s when the operations team began investigating different pieces of hardware on the SI C&DH as the possible source. Based on the available data, the team initially thought that the problem was due to a degrading memory module and tried to switch to one of the module’s multiple backups – but met with failure. On the evening of Thursday, June 17th, another attempt was made to bring both modules back online, but these attempts also led to failure.

At that point, they began looking into other possibles sources of the shutdown, like the Standard Interface (STINT) hardware. This component is responsible for bridging communications between the computer’s Central Processing Module (CPM), which they began investigating as well. Now, the team is investigating the Command Unit/Science Data Formatter (CU/SDF) and a power regulator within the Power Control Unit (PCU).

When Oumuamua, the first interstellar object ever observed passing through the Solar System, was discovered in 2017, it exhibited some unexpected properties that left astronomers scratching their heads. Its elongated shape, lack of a coma, and the fact that it changed its trajectory were all surprising, leading to several competing theories about its origin: was it a hydrogen iceberg exhibiting outgassing, or maybe an extraterrestrial solar sail (sorry folks, not likely) on a deep-space journey? We may never know the answer, because Oumuamua was moving too fast, and was observed too late, to get a good look.

It may be too late for Oumuamua, but we could be ready for the next strange interstellar visitor if we wanted to. A spacecraft could be designed and built to catch such an object at a moment’s notice. The idea of an interstellar interceptor like this has been floated by various experts, and funding to study such a concept has even been granted through NASA’s Innovative Advanced Concepts (NIAC) program. But how exactly would such an interceptor work?

A new paper released on ArXiv on June 27th explores one possible mission design. Derived from the NIAC study, the proposal suggests combining solar sail technology with the ability to miniaturize space probes to small, lightweight sizes.

Missions like JAXA’s IKAROS probe to Venus and the Planetary Society’s ongoing LightSail 2 project in Earth orbit have shown that solar sails, which use photons from the sun to accelerate, are entirely feasible propulsion systems. Similarly, the successful use of CubeSats on interplanetary missions was demonstrated by the Jet Propulsion Laboratory in 2018. They sent two CubeSats, named Mars Cube One (MarCO-a and MarCO-b), to accompany the InSight lander on its journey to the red planet. The CubeSats worked like a charm.

When combined, solar sails and CubeSats could be a powerful tool for exploration.