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On Feb. 5, 1974, NASA's Mariner 10 mission took this first close-up photo of Venus during 1st gravity assist flyby. Credit: NASA
Exactly 40 Years ago today on Feb. 5, 1974, Mariner 10, accomplished a history making and groundbreaking feat when the NASA science probe became the first spacecraft ever to test out and execute the technique known as a planetary gravity assisted flyby used to alter its speed and trajectory – in order to reach another celestial body.
Mariner 10 flew by Venus 40 years ago to enable the probe to gain enough speed and alter its flight path to eventually become humanity’s first spacecraft to reach the planet Mercury, closest to our Sun.
Indeed it was the first spacecraft to visit two planets.
During the flyby precisely four decades ago, Mariner 10 snapped its 1st close up view of Venus – see above.
From that moment forward, gravity assisted slingshot maneuvers became an extremely important technique used numerous times by NASA to carry out planetary exploration missions that would not otherwise have been possible.
For example, NASA’s twin Voyager 1 and 2 probes launched barely three years later in 1977 used the gravity speed boost to conduct their own historic flyby expeditions to our Solar Systems outer planets.
Mariner 10’s Mercury.
This is a photomosaic of images collected by Mariner 10 as it flew past Mercury on 29 March 1974. It shows the southern hemisphere. The spacecraft took more than 7,000 images of Mercury, Venus, the Earth, and the moon during its mission. Credit: NASA
Without the flyby’s, the rocket launchers thrust by themselves did not provide sufficient interplanetary speed to reach their follow on targets.
NASA’s Juno Jupiter orbiter just flew back around Earth this past October 9, 2013 to gain the speed it requires to reach the Jovian system.
The Mariner 10 probe used an ultraviolet filter in its imaging system to bring out details in the Venusian clouds which are otherwise featureless to the human eye – as you’ll notice when viewing it through a telescope.
Venus surface is completely obscured by a thick layer of carbon dioxide clouds.
The hellish planet’s surface temperature is 460 degrees Celsius or 900 degrees Fahrenheit.
Diagram of Mariner 10 which flew by Venus and Mercury in 1974 and 1975. This photo identifies various parts of the spacecraft and the science instruments, which were used to study the atmospheric, surface, and physical characteristics of Venus and Mercury. This was the sixth in the series of Mariner spacecraft that explored the inner planets beginning in 1962. Credit: Jet Propulsion Laboratory
Following the completely successful Venus flyby, Mariner 10 eventually went on to conduct a trio of flyby’s of Mercury in 1974 and 1975.
It imaged nearly half of the planets moon-like surface, found surprising evidence of a magnetic field, discovered that a metallic core comprised nearly 80 percent of the planet’s mass, and measured temperatures ranging from 187°C on the dayside to minus 183°C on the nightside.
Mercury was not visited again for over three decades until NASA’s MESSENGER flew by and eventually orbited the planet – and where it remains active today.
Mariner 10 was launched on Nov. 3, 1973 from the Kennedy Space Center atop an Atlas-Centaur rocket.
Mosaic of the Earth from Mariner 10 after launch. Credit: NASAShortly after blastoff if also took photos of the Earth and the Moon.
Ultimately it was the last of NASA’s venerable Mariner planetary missions hailing from the dawn of the Space Age.
Mariner 11 and 12 were descoped due to congressional budget cuts and eventually renamed as Voyager 1 and 2.
The Mariner 10 science team was led by Bruce Murray of the Jet Propulsion Laboratory (JPL), Pasadena, Calif.
Murray eventually became the Director of JPL. After he passed away in 2013, key science features on Martian mountain climbing destinations were named in his honor by the Opportunity and Curiosity Mars rover science teams.
Stay tuned here for Ken’s continuing LADEE, Chang’e-3, Orion, Orbital Sciences, SpaceX, commercial space, Mars rover and more planetary and human spaceflight news.
Mariner 10 trajectory and timeline to Venus and Mercury. Credit: NASADiagram of the Mariner series of spacecraft and launch vehicle. Mariner spacecraft explored Mercury, Venus and Mars. Credit: Jet Propulsion LaboratoryMosaic of Earth from Juno gravity assist Flyby in 2013 –
compare to Mariner 10 Earth mosaic above from 1973 to see advances in space technology
This false color composite shows more than half of Earth’s disk over the coast of Argentina and the South Atlantic Ocean as the Juno probe slingshotted by on Oct. 9, 2013 for a gravity assisted acceleration to Jupiter. The mosaic was assembled from raw images taken by the Junocam imager. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo
Venus as captured by Shahrin Ahmad (@shahgazer) on January 31st, 2014. Credit- Shahgazer.net.
Are you a chronic early riser? Observational astronomy often means late nights and early mornings as daylight lengths get longer for northern hemisphere residents in February through March. But this year offers another delight for the early morning crowd, as the Venus is hanging out in the dawn skies for most of 2014.
You may have already caught sight of the brilliant world: it’s hard to miss, currently shinning at a dazzling -4.5 magnitude in the dawn. Venus is the brightest planet as seen from Earth and the third brightest natural object in the night sky after the Sun and the Moon.
Venus just passed between the Earth and the Sun last month on January 11th at inferior conjunction. Passing over five degrees north of the Sun, this was a far cry from the historic 2012 transit of the solar disk, a feat that won’t be replicated again until 2117 AD.
But February and March offer some notable events worth watching out for as Venus wanders in the dawn.
The path of Venus from February 4th to September 23rd, 2014. The first (top) graphic lays out the path as seen at dawn from latitude 30 degrees north, while the bottom lays out the path of Venus as seen from latitude 30 degrees south. Note that the orientation of the ecliptic in the top frame is set for September 23rd, while the bottom frame is set for February 4th, respectively. Created using Starry Night Education software.
This week sees Venus thicken as a 48” 16% illuminated waxing crescent as it continues to present more of its daytime side to the Earth. We’ve always thought that it was a bit of cosmic irony that the closest planet too us presents no surface detail to observers: Venus is a cosmic tease. This assured that astronomers knew almost nothing about Venus until the dawn of the Space Age — guesses at its rotational speed and surface conditions were all widely speculative. Ideas of a vast extraterrestrial jungle or surface-spanning seas of seltzer water oceans gave way to the reality of a shrouded hellish inferno with noontime temps approaching 460 degrees Celsius. Venus is also bizarre in the fact that it rotates once every 243 Earth days, which is longer than its 224.7 day year — you could easily out walk a Venusian sunrise, that is if you could somehow survive to see it from its perpetually clouded surface!
Venus also passes 4.3 degrees from faint Pluto this week on February 5th. And while Pluto is a tough catch at over a million times fainter than Venus, it’s interesting to consider that NASA’s New Horizons and ESA’s Rosetta spacecraft are also currently off in the same general direction:
Venus and the invisible lineup of deep space missions in the same general direction this week. Also note that Venus has been skirting the non-zodiacal constellation of Scutum this season! Created using Starry Night Education Software.
Venus also reaches greatest brilliancy at magnitude -4.6 next week on February 11th. Venus is bright enough to cast a shadow onto a high contrast background, such as freshly fallen snow. Can you see your “Venusian shadow” with the naked eye? How about photographically?
Venus then goes on to show its greatest illuminated extent to us on February 15th. This combination occurs because although the crescent of Venus is fattening, the apparent size of the disk is shrinking as the planet pulls away from us in its speedy interior orbit. Can you spy the elusive “ashen light of Venus” through a telescope? Long a controversy, this has been reported by observers as a dim “glow” on the nighttime hemisphere of Venus. Proposed explanations for the ashen light of Venus over the years have been airglow, aurorae, lightning, Venusian land clearing activity (!) or, more likely, an optical illusion.
And speaking of which, the crescent Venus gets occulted by the waning crescent Moon on February 26th. Observers in western Africa will see this occur in the predawn skies, and the rest of us will see a close pass of the pair worldwide. Can you spot Venus near the crescent Moon in the daytime sky on the 26th?
The Moon and Venus at dawn on February 25th for observers along the U.S. Eastern Seaboard. Created using Stellarium.
In March, Venus begins the slide southward towards the point occupied by the Sun months earlier and heads towards its greatest westward elongation for 2014 on March 22nd at 46.6 degrees west of the Sun. Interestingly, Venus is tracing out roughly the same track it took 8 years ago in 2006 and will trace again in 2022, when it will also spend a majority of the year in the dawn once again. The 8-year repeating cycle of Venus is a result of the planet completing very nearly 13 orbits of the Sun to our 8. Ancient cultures, including the Maya, Egyptians, and Babylonian astronomers all knew of this period.
Through the telescope, Venus appears at a tiny “half-moon” phase 50% illuminated at greatest elongation, a point known as dichotomy. It’s interesting to note that theoretical and observed dichotomy can actually vary by several days surrounding greatest elongation. An optical phenomenon, or a true observational occurrence? When do you judge that dichotomy occurs in 2014?
In April, one of the closest planetary conjunctions occurs of 2014 on the 12th involving Neptune and Venus at just 40’ apart, a little over the span of a Full Moon. Can you squeeze both into an eyepiece field of view? At +7.7th magnitude, Neptune shines at over 25,000 times fainter than Venus. Neith, the spurious “moon” of Venus described by 18th century astronomers lives!
But two even more dramatic conjunctions occur late in the summer, when Jupiter passes just 15’ from Venus on August 18th and Regulus stands just 42’ from Venus on September 5th. Fun fact: Venus actually occulted Regulus last century on July 7th, 1959!
From there on out, Venus heads toward superior conjunction on the far side of the Sun on October 25th, to once again emerge into the dusk sky through late 2014 and 2015.
Be sure to check out these dawn exploits of Venus through this Spring season and beyond!
Special Guests: Stephen Pakbaz, designer of the LEGO Mars Rover Kit, and Ray Sanders from CosmoQuest, who is unboxing and building the kit as we hang out!
Venus, 0.4% illuminated and 5.1 degrees from the Sun, as seen about 12:30 pm local noon time from Sri Damansara, Malaysia (0430 UTC) on January 11, 2014, about about 8 hours before inferior conjunction. Credit and copyright: Shahrin Ahmad.
Venus has now gone from being that bright “star” you’ve been seeing around sunset to later this month being the bright object you’ll see in the early morning pre-dawn hours. On January 11, Venus passed between Earth and the Sun in what is known as inferior conjunction. We challenged our readers to try and capture it, and Shahrin Ahmad in Malaysia nabbed the tiny crescent Venus about 8 hours before inferior conjunction, in what he said was a personal record!
“Around 12.30 p.m. local noon time, there was a brief of good seeing, and probably the best one so far,” Shah said via email. “Suits nicely as a parting shot. After that the sky seeing began to deteriorate really fast!”
Venus was about 0.4% illuminated and 5.1 deg from the Sun.
“Even without stretching the original photo, we can easily see how the crescent has reach beyond 180 degrees around Venus,” he said. “This is the closest Venus I’ve ever imaged.”
Venus inferior conjunction timeline from January 7 to 13th, missing January 12 due to clouds. Credit and copyright: Paul Stewart.
Wow! That’s exceptional work! You can see more of Paul’s astro-work at his website, Upside Down Astronomer.
Thanks to both Shah and Paul for sharing their photos!
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
Scott:
Learning tools for visually impaired:
More information on the 3-D Hubble images can be found here
Here’s the press release for the iBook being released Frontier Fields
We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page.
The Moon and Venus, both in crescent phase, as seen from Sulmona, Abruzzo, Italy on January 2, 2014. Credit and copyright: Giuseppe Petricca.
2014 starts out with sunset view of a new Moon and a fading look at Venus, both captured together in this gorgeous image from astrophotographer Giuseppe Petricca.
“A wonderful sunset conjunction this evening from Central Italy,” Giuseppe wrote via email. “The Moon and Venus were both crescent, in an awesome sight! Some clouds entered the scene, and helped me filter the bright light of the ‘evening star’, revealing the little arch of the planet, from our point of view.” He added that this is “the youngest Moon I’ve ever captured, about 2% lit.”
Below is an image with an inset of Venus enlarged for a better view:
The Moon and Venus, both in crescent phase, as seen from Sulmona, Abruzzo, Italy on January 2, 2014. Inset shows Venus enlarged. Credit and copyright: Giuseppe Petricca.
As our writer Bob King noted in his recent article, catch Venus now while you can, as it is slipping away: “As 2013 gives way to the new year, Venus winds up its evening presentation as it prepares to transition to the morning sky. Catch it while you can. Each passing night sees the planet dropping ever closer to the horizon as its apparent distance from the sun shrinks. On January 11 it will pass through inferior conjunction as it glides between Earth and Sun.”
Giuseppe’s images were taken with a simple non-reflex camera on a tripod, Nikon P90, ISO 100, f5.0, 1/2 exposure, which he says demonstrates “that with a little effort, you don’t need an expensive digicam to take this kind of shot.”
Venus visible in the daytime skies over Kuala Lumpur on January 2, 2014. Credit and copyright: Shahrin Ahmad.
In December, we challenged our readers to try and see Venus during the daytime. Sharin Ahmad from Kuala Lumpur, Malaysia started off the new year by nailing this awesome picture of a crescent Venus at just after noon local time today (January 2, 2014). “The usual cloudy Kuala Lumpur sky is teasing me again, giving me crystal blue sky today!” Shahrin said via email.
Based on SkySafari, Venus was about 3.2% illuminated, and about 15 degrees from Sun.
Equipment: Skywatcher 120ED (F=1800mm), and IMG132E video camera.
Here are other recent images of Venus submitted to our Flickr page by our readers:
Crescent Venus on Dec. 31, 2013, seen from Arizona. Credit and copyright: Robert Sparks.
The color of Venus: Three images of Venus taken on January 1, 2014. Credit and copyright: Sergei Golyshev .
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
