Friday, October 19, 2018

NASA wants to send humans to Venus – the brilliant idea laid out




Popular science fiction of the early 20th century depicted Venus as some kind of wonderland of pleasantly warm temperatures, forests, swamps and even dinosaurs. In 1950, the Hayden Planetarium at the American Natural History Museum were soliciting reservations for the first space tourism mission, well before the modern era of Blue Origins, SpaceX and Virgin Galactic. All you had to do was supply your address and tick the box for your preferred destination, which included Venus.
Today, Venus is unlikely to be a dream destination for aspiring space tourists. As revealed by numerous missions in the last few decades, rather than being a paradise, the planet is a hellish world of infernal temperatures, a corrosive toxic atmosphere and crushing pressures at the surface. Despite this, NASA is currently working on a conceptual manned mission to Venus, named the High Altitude Venus Operational Concept – (HAVOC).
But how is such a mission even possible? Temperatures on the planet’s surface (about 460°C) are in fact hotter than Mercury, even though Venus is roughly double the distance from the sun. This is higher than the melting point of many metals including bismuth and lead, which may even fall as “snow” onto the higher mountain peaks. The surface is a barren rocky landscape consisting of vast plains of basaltic rock dotted with volcanic features, and several continent-scale mountainous regions.


Venus was once an Earth twin. NASA / JPL

It is also geologically young, having undergone catastrophic resurfacing events. Such extreme events are caused by the build up of heat below the surface, eventually causing it to melt, release heat and re-solidify. Certainly a scary prospect for any visitors.

Hovering in the atmosphere

Luckily, the idea behind NASA’s new mission is not to land people on the inhospitable surface, but to use the dense atmosphere as a base for exploration. No actual date for a HAVOC type mission has been publicly announced yet. This mission is a long term plan and will rely on small test missions to be successful first. Such a mission is actually possible, right now, with current technology. The plan is to use airships which can stay aloft in the upper atmosphere for extended periods of time.
As surprising as it may seem, the upper atmosphere of Venus is the most Earth-like location in the solar system. Between altitudes of 50km and 60km, the pressure and temperature can be compared to regions of the Earth’s lower atmosphere. The atmospheric pressure in the Venusian atmosphere at 55km is about half that of the pressure at sea level on Earth. In fact you would be fine without a pressure suit, as this is roughly equivalent to the air pressure you would encounter at the summit of Mount Kilimanjaro. Nor would you need to insulate yourself as the temperature here ranges between 20°C and 30°C.
The atmosphere above this altitude is also dense enough to protect astronauts from ionising radiation from space. The closer proximity of the sun provides an even greater abundance of available solar radiation than on Earth, which can be used to generate power (approximately 1.4 times greater).
The conceptual airship would float around the planet, being blown by the wind. It could, usefully, be filled with a breathable gas mixture such as oxygen and nitrogen, providing buoyancy. This is possible because breathable air is less dense than the Venusian atmosphere and, as result, would be a lifting gas.
The Venusian atmosphere is comprised of 97% carbon dioxide, about 3% nitrogen and trace amounts of other gases. It famously contains a sprinkling of sulphuric acid which forms dense clouds and is a major contributor to its visible brightness when viewed from Earth. In fact the planet reflects some 75% of the light that falls onto it from the sun. This highly reflective cloud layer exists between 45km and 65km, with a haze of sulphuric acid droplets underneath down to about 30km. As such, an airship design would need to be resistant to the corrosive effect of this acid.
Luckily we already have the technology required to overcome the problem of acidity. Several commercially available materials, including teflon and a number of plastics, have a high acidic resistance and could be used for the outer envelope of the airship. Considering all these factors, conceivably you could go for a walk on a platform outside the airship, carrying only your air supply and wearing a chemical hazard suit.

Life on Venus?

The surface of Venus has been mapped from orbit by radar on the US Magellan mission. However, only a few locations on the surface have ever been visited, by the series of Venera missions of Soviet probes in the late 1970s. These probes returned the first – and so far only – images of the Venusian surface. Certainly surface conditions seem utterly inhospitable to any kind of life.


Venus as seen by Magellan. NASA

The upper atmosphere is a different story however. Certain kinds of extremophile organisms already exist on Earth which could withstand the conditions in the atmosphere at the altitude at which HAVOC would fly. Species such as Acidianus infernus can be found in highly acidic volcanic lakes in Iceland and Italy. Airborne microbes have also been found to exist in Earth’s clouds. None of this proves that life exists in the Venusian atmosphere, but it is a possibility that could be investigated by a mission like HAVOC.
The current climatic conditions and composition of the atmosphere are the result of a runaway greenhouse effect (an extreme greenhouse effect that cannot be reversed), which transformed the planet from a hospitable Earth-like “twin” world in its early history. While we do not currently expect Earth to undergo a similarly extreme scenario, it does demonstrate that dramatic changes to a planetary climate can happen when certain physical conditions arise.
By testing our current climate models using the extremes seen on Venus we can more accurately determine how various climate forcing effects can lead to dramatic changes. Venus therefore provides us with a means to test the extremes of our current climate modelling, with all the inherent implications for the ecological health of our own planet.
We still know relatively little about Venus, despite it being our nearest planetary neighbour. Ultimately, learning how two very similar planets can have such different pasts will help us understand the evolution of the solar system and perhaps even that of other star systems.
Gareth Dorrian, Post Doctoral Research Associate in Space Science, Nottingham Trent University and Ian Whittaker, Lecturer, Nottingham Trent University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Thursday, October 18, 2018

Giant Supercluster Discovered in the Early Universe

   A international team of astronomers has discovered a gigantic structure in the early universe which existed about 2 billion years after the Big Bang. Hyperion, a galaxy proto-supercluster, is the largest and most massive structure discovered to date in the early universe.
   The team which includes scientists from the Istituto Nazionale di Astrofisica (INAF) in Bologna, Italy, and the University of California, Davis, used the VIMOS instrument on ESO's Very large Telescope in Paranal, Chile to identify the galaxies.
   Hyperion is estimated to have a combined mass of over 1 million billion times that of the sun. This enormous mass is comparable to the largest structures observed in the universe today, making this discovery very surprising for many astronomers.
   Found in the constellation of Sextans (the Sextant), the team noticed that Hyperion has a very complex structure. This includes seven high-density regions connected by filaments of galaxies. These regions differ to superclusters found today as their masses are distributed much more uniformly in a series of connected blobs with loose associations of galaxies.

Read the full press release at: https://www.ucdavis.edu/news/astronomers-find-cosmic-titan-early-universe
Find the research study titled "The Progeny of a Cosmic Titan" in the latest issue of the journal Astronomy & Astrophysics.https://arxiv.org/abs/1806.06073

Tuesday, October 16, 2018

Scientists Sequence Genome of Lavender

   A team of scientists at Brock University and the University of British Columbia has sequenced the genome of English lavender (Lavandula angustifolia), a plant that is widely grown around the world.
   Creating the first draft genome assembly for English lavender, the researchers found that lavender has a moderately repeated (over 48% repeated elements) genome of 870 million base pairs. This comes out to 62,141 protein-coding genes and 2,003 RNA-coding genes.
   “Researchers now have access to the lavender genome sequence and from here, they can discover more about the plant,” said Dr. Ping Liang of Brock University. “Given the economic status of lavender and its applications of essential oils in many industries, the lavender draft genome sequence serves as a significant genetic resource for continued lavender research.”
   Used widely throughout the world in various products such as perfumes, pharmaceutical preparations, cosmetics and antiseptics, lavender and its hybrid counterparts are valued for their essential oils. With production rates reaching over 1,500 metric tons annually, lavender plays a large role in the multi-billion-dollar flavour and fragrance industry worldwide.

Read more about this fascinating story at: http://www.sci-news.com/genetics/lavender-genome-06501.html

Image credit: Rebekka D.

Thursday, October 11, 2018

Lockheed Martin Releases Mega-Lunar Lander Proposal



   Aerospace giant Lockheed Martin has released its latest proposal for a "crewed lunar lander" and it is quite ambitious in terms of industry standards.
    With the Trump administration's principal human spaceflight goal for the near-term being the moon, NASA has begun accepting pitch ideas from companies on how this could be accomplished. As the company building the Orion spacecraft for NASA to carry its astronauts into deep space, Lockheed Martin decided to weigh in with its expertise in space transportation.
 
The lander would incorporate many aspects of the existing Orion design.
 
    Measuring at 14 metres, the single-stage spacecraft can carry up to four astronauts to the lunar surface for up to 14 days.The lander would have carry a considerable mass - 22 metric tons - and would require an additional 40 tons of liquid oxygen and hydrogen fuel to travel between the Moon and the proposed Lunar Gateway. This reusable vehicle could be re-fuelled on the surface of the Moon or in orbit, with at least five to ten flights within its lifespan.
 
 

   Lockheed Martin decided to design such a bulky lander for several reasons. To comply with NASA administrator Jim Bridenstine's wishes, the lunar lander was made to be reusable. Furthermore, the basic design of the spacecraft is built around the same barrel and cone structures of the Orion spacecraft. Most importantly, all of this technology could eventually be adapted for a lander in a future humans-to-Mars exploration mission.


Image Credit: Lockheed Martin

Sunday, October 7, 2018

Astronomers May Have Discovered the First-Ever Exomoon

   This week, scientists presented new observations from the Kepler and Hubble space telescopes that suggest the discovery of an exomoon. These foreign moons are the natural satellites of planets orbiting stars outside of our solar system, of which there are no currently confirmed cases.
   The exomoon candidate orbits around an exoplanet called Kepler-1625b. Located about 8000 light-years away from Earth, this planet is likely several Jupiter masses while the exomoon has a mass and radius similar to Neptune.
   The scientists advocate in favour of their moon hypothesis due to a collection of factors including timing deviations and a flux decrement from the star.
   During observation of the star, it was noticed that there were weird deviations in the 'light curve' generated by the 19-hour-long transit of the planet. Further observation revealed an additional decrease in the star's brightness after the planet transits its star.
   "The first is that the planet appears to transit one and a quarter hours too early; that’s indicative of something gravitationally tugging on the planet," said co-author David Kipping of Columbia University. "The second anomaly is an additional decrease in the star’s brightness after the planetary transit has completed."
   "We hope to re-observe the star again in the future to verify or reject the exomoon hypothesis," Kipping said. "And if validated, the planet-moon system — a Jupiter with a Neptune-sized moon — would be a remarkable system with unanticipated properties, in many ways echoing the unexpected discovery of hot Jupiters in the early days of planet hunting." 
Image Credit: Dan Durda

Saturday, October 6, 2018

Photo of the Week

This week for Photo of the Week, we would like to feature a spectacular photo of the constellation Scorpius. Taken by the photographer Yuriy Toropin, this beautiful photo features some of the most colourful parts of the night sky, located conveniently close to the centre of the Milky Way. Visible in this photo are the nebulae IC4592 at the bottom left and IC 4604, also known as the Rho Ophiuchi cloud complex, at the top right.
 
For more fantastic photos, be sure to check out more of Toropin's photos at: https://www.flickr.com/photos/ytoropin/

Thursday, September 27, 2018

Photo of the Week

 This week for Photo of the Week, we would like to feature an amazing photo of the Milky Way over Lake Tahoe. Captured by the talented photographer Dave Morrow, this beautiful photo displays some of the beautiful landscape visible along this interstate lake including the impressive Sierra Nevada mountain range in the background. Featured in the foreground is the Bonsai Rock, with its reflection visible in the clear waters of the lake.
 For more fantastic photos, be sure to check out Morrow's Flickr at: https://www.flickr.com/photos/daves-f-stop/