A Day in Astronomy: Pioneer Venus

Posted on by onespaceman2000
Image (Credit): Artist’s version of the Pioneer Venus Orbiter above Venus. (NASA)

On this day in 1978, NASA launched Pioneer Venus from Cape Canaveral, Florida. The mission had two components:

  • the Pioneer Venus Orbiter that remained in orbit around the planet until 1992 when it entered the Venusian atmosphere and burned up, and
  • the Pioneer Venus Multiprobe (known as Pioneer 13) that carried four probes later dropped into the Venusian atmosphere.

NASA described the descent of the four probes:

When the probes separated from the Multiprobe bus, they went “off the air” because they did not have sufficient on-board power or solar cells to replenish their batteries. Preprogrammed instructions were wired into them and their timers had been set before they separated from the bus. The on-board countdown timers were scheduled to bring each probe into operation again three hours before the probes began their descent through the Venusian atmosphere. On 9 December 1978, just 22 minutes before entry, the Large Probe began to transmit radio signals to Earth. Only 17 minutes before hurtling into the Venusian atmosphere at almost 42,000 km/hr (26,100 mph), all the Small Probes started transmitting.

All four probes were designed for a descent time of approximately 55 minutes before impacting the surface. None were designed to withstand the impact. However one Small Probe (the Day Probe) did survive and sent data from the surface for 67 minutes. Engineering data radioed back from the Day Probe showed that its internal temperature climbed steadily to a high of 126 degrees C (260 degrees F). Then its batteries were depleted, and its radio became silent.

A 2020 Nature Astronomy article noted that one of the probes may have detected signs of life in the Venusian atmosphere. The paper, Phosphine Gas in the Cloud Decks of Venus, has been controversial and was later modified to clarify some of the findings. However, a separate study in the Geophysical Research Letter, Venus’ Mass Spectra Show Signs of Disequilibria in the Middle Clouds, confirmed some of these finding and adding to the argument with the discovery of other chemicals that could also be linked to biological processes. The debate will continue as we learn more.

Image (Credit): The four terrestrial planets of our inner Solar System: Mercury, Venus, Earth and Mars. These images were taken by the Mariner 10, Apollo 17 and Viking missions. (European Space Agency)

The Chairwoman of the UAE Space Agency and the Mission to Mars

Posted on by onespaceman2000
Image (Credit): Artist’s image of UAE’s Hope probe orbiting Mars. (UAE Space Agency)

You may want to visit Time magazine and view the article “The Woman Who Took the UAE to Mars.” It summarizes Sarah Al Amiri’s efforts related to the United Arab Emirates’ mission to Mars as well as her plans for the country’s space agency, which she now heads as Chairwoman.

Prior to becoming Chairwoman, Ms. Amiri was deputy project manager of a mission to map the Martian atmosphere. Her team, which was 80 percent female, developed the Hope probe to accomplish this goal. The probe was launched aboard a Japanese rocket in July 2020 and now orbits Mars. The data obtained from this mission is being shared openly to assist others studying the Martian atmosphere.

Another mission mentioned in the Time article by Chairwoman Amiri is a tour of seven asteroids as well as a flyby of Venus. A UAE space page defines the mission in this way:

The spacecraft will undertake a 3.6 billion-kilometre, five-year journey, which will see it perform gravity assist manoeuvres by orbiting first Venus, then Earth in order to build the velocity required in order to reach the main asteroid belt, located beyond Mars…The mission will study seven main belt asteroids…The mission will make its first close planetary approach orbiting Venus in mid-2028, followed by a close orbit of Earth in mid-2029. It will make its first fly-by of a main asteroid belt object in 2030, going on to observe a total of seven main belt asteroids before its final landing on an asteroid 560 million kilometres from Earth in 2033. This will make the Emirates the fourth nation to land a spacecraft on an asteroid.

What was not mentioned in the story but is available via another UAE government page is plans for several other space endeavors, including:

  • Sending a rover to the Moon in 2024. The rover’s name is Rashid, named in honor of the late Sheikh Rashid bin Saeed Al Maktoum, former Ruler of Dubai.
  • Establishing a settlement on Mars by 2117, and building a Mars Science City within the UAE to make this Martian mission possible.

Should We Return to Uranus?

Posted on by onespaceman2000
Source/Credit: A NASA composite image of Uranus taken from Voyager 2 and the Hubble Space Telescope.

In an earlier posting, I highlighted some scientific papers calling for a return to Neptune rather than Uranus, in part because of Neptune’s moon Triton. But what is the argument for a mission to Uranus? Below I highlight one of the papers submitted to the Planetary Science and Astrobiology Decadal Survey 2023-2032 arguing the merits of a NASA mission to Uranus.

The paper, “The Science Case for Spacecraft Exploration of the Uranian Satellites,” states:

The large moons of Uranus are possible ocean worlds that exhibit a variety of surface features, hinting at endogenic geologic activity in the recent past. These moons are rich in water ice, as well as carbon-bearing and likely nitrogen-bearing constituents, which represent some of the key components for life as we know it. However, our understanding of Uranus and its moons is severely limited by the absence of data collected by an orbiting spacecraft…

An orbiter would vastly improve our understanding of these possible ocean worlds and allow us to assess the nature of water and organics in the Uranian system, thereby improving our knowledge of these moons’ astrobiological potential. A Flagship mission to Uranus can be carried out with existing chemical propulsion technology by making use of a Jupiter gravity assist in the 2030 – 2034 timeframe, leading to a flight time of only ~11 years, arriving in the early to mid 2040’s (outlined in the Ice Giants Pre-Decadal Survey Mission Study Report: https://www.lpi.usra.edu/icegiants/mission_study/Full-Report.pdf).

The five large moons discussed in the paper are Miranda, Ariel, Umbriel, Titania, and Oberon. Titania and Oberon where the first to be discovered back in 1787, followed by the later discoveries of Ariel, Umbriel, and Miranda (in that order). Unlike the moons of other planets, the moons of Uranus are named after magical spirits in English literature.

All of these ocean worlds have gained greater interest as we learn about the dynamics of life on of our own planet. As noted in an article in the MIT Technology Review:

It was once thought the solar system was probably a barren wasteland apart from Earth. Rocky neighbors were too dry and cold like Mars, or too hot and hellish like Venus. The other planets were gas giants, and life on those worlds or their satellite moons was basically inconceivable. Earth seemed to be a miracle of a miracle.

But life isn’t that simple. We now know that life on Earth is able to thrive in even the harshest, most brutal environments, in super cold and super dry conditions, depths of unimaginable pressures, and without the need to use sunlight as a source of energy. At the same time, our cursory understanding of these obscure worlds has expanded tremendously. 

We have plenty of worlds to explore in our own solar system as other scientists continue their search for exoplanets and exomoons. The only question now is which local worlds will we visit in our next round of space missions.

Private Space Missions: Is Venus Next?

Posted on by onespaceman2000
Source/Credit: Venus from Mattias Malmer/NASA/JPL..

NBC news reports that a privately-funding space probe could visit Venus as early as next year as phase one of a three-part mission. The goal of the Venus Life Finder Mission, involving MIT alumni and Rocket Lab, is to search for signs of life or microbial-type life. This effort is another encouraging sign of increased interest in scientific missions throughout the solar system.

An earlier press release on the Venus Life Finder site stated:

The Venus Life Finder Missions are a series of focused astrobiology mission concepts to search for habitability, signs of life, and life itself in the Venus atmosphere. While people have speculated on life in the Venus clouds for decades, we are now able to act with cost-effective and highly-focused missions. A major motivation are unexplained atmospheric chemical anomalies, including the “mysterious UV-absorber”, tens of ppm O2,  SO2 and H2O vertical abundance profiles, the possible presence of PH3 and NH3, and the unknown composition of Mode 3 cloud particles. These anomalies, which have lingered for decades, might be tied to habitability and life’s activities or be indicative of unknown chemistry itself worth exploring.  Our proposed series of VLF missions aim to study Venus’ cloud particles and to continue where the pioneering in situ probe missions from nearly four decades ago left off. The world is poised on the brink of a revolution in space science. Our goal is not to supplant any other efforts but to take advantage of an opportunity for high-risk, high-reward science, which stands to possibly answer one of the greatest scientific mysteries of all, and in the process pioneer a new model of private/public partnership in space exploration.

It has been more than a decade since a government has sent a mission to Venus. The last US mission to Venus was the Magellan launched in May 1989, which started to orbit Venus in 1990 and continued to do so for four years. The European Space Agency sent the Venus Express to the planet in November 2005, while Japan sent the Akatsuki in May 2010.

Interest continues among government parties. For example, just last year NASA announced two new missions to Venus:

— DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging) to measure the composition of Venus’ atmosphere to understand how it formed and evolved, as well as determine whether the planet ever had an ocean. The mission consists of a descent sphere that will plunge through the planet’s thick atmosphere, making precise measurements of noble gases and other elements to understand why Venus’ atmosphere is a runaway hothouse compared the Earth’s. It will also will return the first high resolution pictures of the unique geological features on Venus known as “tesserae,” which may be comparable to Earth’s continents, suggesting that Venus has plate tectonics.

— VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) to map Venus’ surface to determine the planet’s geologic history and understand why it developed so differently than Earth. In addition, it will map infrared emissions from Venus’ surface to map its rock type, which is largely unknown, and determine whether active volcanoes are releasing water vapor into the atmosphere. 

Source: Venuscloudlife.com.

NASA’s Travel Agency

Posted on by onespaceman2000
Source: NASA’s Jet Propulsion Laboratory.

If you are getting tired of staying home these days, NASA has some fun destinations in mind for you. Late last year, NASA’s Jet Propulsion Laboratory (JPL) put together “Visions of the Future” to show you where the space agency hopes to go someday. You may not want to pack just yet, but whether it is this solar system or some other solar system, NASA wants to help.

The poster above for Kepler-16b comes with this enticing description:

Like Luke Skywalker’s planet “Tatooine” in Star Wars, Kepler-16b orbits a pair of stars. Depicted here as a terrestrial planet, Kepler-16b might also be a gas giant like Saturn. Prospects for life on this unusual world aren’t good, as it has a temperature similar to that of dry ice. But the discovery indicates that the movie’s iconic double-sunset is anything but science fiction.

You might also enjoy this NASA video showing some space activities in these prime locations.

I dropped in a few more posters below, but be sure to check out all of them. A big thanks also to the folks at JPL for these fun images. The 14 posters were created by nine artists, designers, and illustrators.

Of course, these free photos are already being sold on Etsy.com and elsewhere as posters and t-shirts.

Source: NASA’s Jet Propulsion Laboratory.
Source: NASA’s Jet Propulsion Laboratory.