Science Current Events | Science News |

Hubble to use moon as mirror to see Venus transit

May 07, 2012
This mottled landscape showing the impact crater Tycho is among the most violent-looking places on our moon. Astronomers didn't aim NASA's Hubble Space Telescope to study Tycho, however. The image was taken in preparation to observe the transit of Venus across the sun's face on June 5-6.

Hubble cannot look at the sun directly, so astronomers are planning to point the telescope at the Earth's moon, using it as a mirror to capture reflected sunlight and isolate the small fraction of the light that passes through Venus's atmosphere. Imprinted on that small amount of light are the fingerprints of the planet's atmospheric makeup.

These observations will mimic a technique that is already being used to sample the atmospheres of giant planets outside our solar system passing in front of their stars. In the case of the Venus transit observations, astronomers already know the chemical makeup of Venus's atmosphere, and that it does not show signs of life on the planet. But the Venus transit will be used to test whether this technique will have a chance of detecting the very faint fingerprints of an Earth-like planet, even one that might be habitable for life, outside our solar system that similarly transits its own star. , Venus is an excellent proxy because it is similar in size and mass to our planet.

The astronomers will use an arsenal of Hubble instruments, the Advanced Camera for Surveys, Wide Field Camera 3, and Space Telescope Imaging Spectrograph, to view the transit in a range of wavelengths, from ultraviolet to near-infrared light. During the transit, Hubble will snap images and perform spectroscopy, dividing the sunlight into its constituent colors, which could yield information about the makeup of Venus's atmosphere.

Hubble will observe the moon for seven hours, before, during, and after the transit so the astronomers can compare the data. Astronomers need the long observation because they are looking for extremely faint spectral signatures. Only 1/100,000th of the sunlight will filter through Venus's atmosphere and be reflected off the moon.

This image, taken with Hubble's Advanced Camera for Surveys, reveals lunar features as small as roughly 560 feet (170 meters) across. The large "bulls-eye" near the top of the picture is the impact crater, caused by an asteroid strike about 100 million years ago. The bright trails radiating from the crater were formed by material ejected from the impact area during the asteroid collision. Tycho is about 50 miles (80 kilometers) wide and is circled by a rim of material rising almost 3 miles (5 kilometers) above the crater floor. The image measures 430 miles (700 kilometers) across, which is slightly larger than New Mexico.

Because the astronomers only have one shot at observing the transit, they had to carefully plan how the study would be carried out. Part of their planning included the test observations of the moon, made on Jan. 11, 2012, as shown in the release image.

Hubble will need to be locked onto the same location on the moon for more than seven hours, the transit's duration. For roughly 40 minutes of each 96-minute orbit of Hubble around the Earth, the Earth occults Hubble's view of the moon. So, during the test observations, the astronomers wanted to make sure they could point Hubble to precisely the same target area.

This is the last time this century sky watchers can view Venus passing in front of the sun. The next transit won't happen until 2117. Venus transits occur in pairs, separated by eight years. The last event was witnessed in 2004.

NASA/Goddard Space Flight Center

Related Impact Crater Current Events and Impact Crater News Articles

Violent solar system history uncovered by WA meteorite
Curtin University planetary scientists have shed some light on the bombardment history of our solar system by studying a unique volcanic meteorite recovered in Western Australia.

Lunar Pits Could Shelter Astronauts, Reveal Details of How 'Man in the Moon' Formed
While the moon's surface is battered by millions of craters, it also has over 200 holes - steep-walled pits that in some cases might lead to caves that future astronauts could explore and use for shelter, according to new observations from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft.

Ancient crater could hold clues about moon's mantle
Researchers from Brown University and the University of Hawaii have found some mineralogical surprises in the Moon's largest impact crater.

Prehistoric climate change due to cosmic crash in Canada
For the first time, a dramatic global climate shift has been linked to the impact in Quebec of an asteroid or comet, Dartmouth researchers and their colleagues report in a new study.

EARTH: Iowa impact crater confirmed
Scientists have recently confirmed the existence of an impact crater buried below the town of Decorah, Iowa.

How should geophysics contribute to disaster planning?
Earthquakes, tsunamis, and other natural disasters often showcase the worst in human suffering - especially when those disasters strike populations who live in rapidly growing communities in the developing world with poorly enforced or non-existent building codes.

Dartmouth researchers say a comet killed the dinosaurs
In a geological moment about 66 million years ago, something killed off almost all the dinosaurs and some 70 percent of all other species living on Earth.

How does a volcanic crater grow? Grab some TNT and find out
A new University at Buffalo study in the journal Geophysical Research Letters examines maar craters, which resemble the bowl-like cavities formed by meteorites but are in some ways more mysterious.

Mass extinction study provides lessons for modern world
The Cretaceous Period of Earth history ended with a mass extinction that wiped out numerous species, most famously the dinosaurs.

CU-Boulder researchers catalog more than 635,000 Martian craters
It's no secret that Mars is a beaten and battered planet -- astronomers have been peering for centuries at the violent impact craters created by cosmic buckshot pounding its surface over billions of years. But just how beat up is it?
More Impact Crater Current Events and Impact Crater News Articles

Impact Craters of Earth: with Selected Craters Elsewhere

Impact Craters of Earth: with Selected Craters Elsewhere
by Thomas Wm. Hamilton (Author)

Craters have been found on planets and moons throughout the solar system, caused when asteroids or meteors have collided with them. Our Earth has not escaped these impacts, and nearly 200 craters are known on Earth today. Some are easily visited, others are in locations few would ever want to get near. This book details all the known terrestrial impact craters, telling their age, size, and other details, as well as highlighting those easily visited. One has an annual "Craterfest" to attract tourists, while it is possible to swim in lakes that have filled others. Thomas Wm. Hamilton is a retired astronomer who worked for three years on the Apollo Project. He taught astronomy for 32 years, and worked in several planetariums. This is his fifth book on an astronomical topic since his...

Impact Cratering: Processes and Products

Impact Cratering: Processes and Products
by G. R. Osinski (Author), E. Pierazzo (Author)

Impact cratering is arguably the most ubiquitous geological process in the Solar System. It has played an important role in Earth’s history, shaping the geological landscape, affecting the evolution of life, and generating economic resources. However, it was only in the latter half of the 20th century that the importance of impact cratering as a geological process was recognized and only during the past couple of decades that the study of meteorite impact structures has moved into the mainstream. This book seeks to fill a critical gap in the literature by providing an overview text covering broad aspects of the impact cratering process and aimed at graduate students, professionals and researchers alike. It introduces readers to the threat and nature of impactors, the impact cratering...

Meteorite Craters and Impact Structures of the Earth

Meteorite Craters and Impact Structures of the Earth
by Paul Hodge (Author)

During its five-billion-year history, Earth has been hit countless times by asteroids and meteorites. Over 150 crater-producing events have been identified, and this 1994 book describes all 139 sites worldwide at which evidence of the impacts can be seen. They range in age from recent craters formed this century to the highly eroded billion-year-old ancient craters. Some are spectacular to visit, such as the Barringer Crater in Arizona, the ring-shaped mountains of Gosses Bluff, Australia, and the huge crater at Ries in Germany. For each site there is a summary table giving location, size, age and present condition. Maps are included where necessary. The author has visited many of the sites and his photographs enrich this thorough survey. Meteorite craters are fascinating to visit, so the...

Sites of Impact: Meteorite Craters Around the World

Sites of Impact: Meteorite Craters Around the World
by Stan Gaz (Author)

The Earth is pockmarked with the evidence of ancient collisions: huge craters blasted into its surface by thousands of pounds of meteorite fragments traveling at approximately 50,000 miles per hour. Ranging in age from those formed in this century to billion-year-old specimens, the Earth's meteorite craters are eroding at a rapid pace. The best-preserved impact sites are often difficult to accessburied under ice, obscured by foliage, or baking in desert climes. These desolate landscapes are connected to another place outside of our world, and for photographer Stan Gaz they are sites of pilgrimagesteps in a journey begun as a curious young boy accompanying his father on geological expeditions, and culminating in a six-year journey traveling the globe in search of these sites, much of that...

The Asteroid Impact Connection of Planetary Evolution: With Special Reference to Large Precambrian and Australian impacts (SpringerBriefs in Earth Sciences)

The Asteroid Impact Connection of Planetary Evolution: With Special Reference to Large Precambrian and Australian impacts (SpringerBriefs in Earth Sciences)
by Andrew Y. Glikson (Author)

When in 1981 Louis and Walter Alvarez, the father and son team, unearthed a tell-tale Iridium-rich sedimentary horizon at the 65 million years-old Cretaceous-Tertiary boundary at Gubbio, Italy, their find heralded a paradigm shift in the study of terrestrial evolution.  Since the 1980s the discovery and study of asteroid impact ejecta in the oldest well-preserved terrains of Western Australia and South Africa, by Don Lowe, Gary Byerly, Bruce Simonson, Scott Hassler, the author and others, and the documentation of new exposed and buried impact structures in several continents, have led to a resurgence of the idea of the catastrophism theory of Cuvier, previously largely supplanted by the uniformitarian theory of Hutton and Lyell. Several mass extinction of species events are known to have...

"T. rex" and the Crater of Doom (Princeton Science Library)

"T. rex" and the Crater of Doom (Princeton Science Library)
by Walter Alvarez (Author), Carl Zimmer (Foreword)

Sixty-five million years ago, a comet or asteroid larger than Mt. Everest slammed into the Earth, causing an explosion equivalent to the detonation of a hundred million hydrogen bombs. Vaporized impactor and debris from the impact site were blasted out through the atmosphere, falling back to Earth all around the globe. Terrible environmental disasters ensued, including a giant tsunami, continent-scale wildfires, darkness, and cold, followed by sweltering greenhouse heat. When conditions returned to normal, half the genera of plants and animals on Earth had perished. This horrific story is now widely accepted as the solution to a great scientific murder mystery: what caused the extinction of the dinosaurs? In T. rex and the Crater of Doom, the story of the scientific detective work that...

  Impact Craters in South America (SpringerBriefs in Earth System Sciences)
by Rogelio Daniel Acevedo (Author), Maximiliano C. L. Rocca (Author), Juan Federico Ponce (Author), Sergio G. Stinco (Author)

A complete and updated catalogue of impact craters and structures in South America from 2014 is presented here. Approximately eighty proven, suspected and disproven structures have been identified by several sources in this continent. All the impact sites of this large continent have been exhaustively reviewed: the proved ones, the possible ones and some very doubtful. Many sites remain without a clear geological "in situ" confirmation and some of them could be even rejected. Argentina and Brazil are leading the list containing almost everything detected. In Bolivia, Chile, Colombia, Guyana, Paraguay, Perú, Uruguay and Venezuela only a few were observed. Only Ecuador is waiting for new discoveries. So far, the largest well stated impact site is still the Araguainha structure in Brazil...

WHEN THE SKY CRASHED DOWN!: A radical reappraisal of the existence, origins and endings of the Ice Ages, Cosmic Impacts and the Great Extinction Events as well as the origins of life on Earth.

WHEN THE SKY CRASHED DOWN!: A radical reappraisal of the existence, origins and endings of the Ice Ages, Cosmic Impacts and the Great Extinction Events as well as the origins of life on Earth.

A history of massive impacts of cosmic bodies that have shattered the peace and calm of the planet and at times have led to the almost complete extinction of life on our planet, and as we have seen the possible introduction of life as well. We have found that there were no Ice Ages as such but misidentified Polar ice masses relative to where the Poles would have been. We do not live on a gentle planet with subtle million year old changes but a planet subject to massive and sudden change. These changes caused the extinction of many of the creatures that inhabited the earth. And these changes almost caused the extinction of man, possibly several times.

The Chesapeake Bay Crater: Geology and Geophysics of a Late Eocene Submarine Impact Structure (Impact Studies)

The Chesapeake Bay Crater: Geology and Geophysics of a Late Eocene Submarine Impact Structure (Impact Studies)
by Wylie Poag (Author), Christian Koeberl (Author), Wolf Uwe Reimold (Author)

The authors have synthesized 16 years of geological and geophysical studies which document an 85-km-wide impact crater buried 500 m beneath Chesapeake Bay in south eastern Virginia, USA. In doing so, they have integrated extensive seismic reflection profiling and deep core drilling to analyze the structure, morphology, gravimetrics, sedimentology, petrology, geochemistry, and paleontology of this submarine structure. Of special interest are a detailed comparison with other terrestrial and extraterrestrial craters, as well as a conceptual model and computer simulation of the impact. The extensive illustrations encompass more than 150 line drawings and core photographs.

What If?: Serious Scientific Answers to Absurd Hypothetical Questions

What If?: Serious Scientific Answers to Absurd Hypothetical Questions
by Randall Munroe (Author)

From the creator of the wildly popular webcomic xkcd, hilarious and informative answers to important questions you probably never thought to ask. Millions of people visit each week to read Randall Munroe’s iconic webcomic. His stick-figure drawings about science, technology, language, and love have a large and passionate following. Fans of xkcd ask Munroe a lot of strange questions. What if you tried to hit a baseball pitched at 90 percent the speed of light? How fast can you hit a speed bump while driving and live? If there was a robot apocalypse, how long would humanity last? In pursuit of answers, Munroe runs computer simulations, pores over stacks of declassified military research memos, solves differential equations, and consults with nuclear reactor operators. His...

© 2014