Neptune: The Other Blue Planet
by: Jenny Wu
Known Information:
Namesake: Neptune, the Roman god of the sea. Neptune’s blue color, which was caused by its hydrogen, helium, methane composition, was the reason it was why it was named after the god of the sea.
Planet Position: Neptune is officially the eighth and last planet from the sun.
Anomalies: In 1979, Neptune was further from the sun than Pluto. On February 11, 1999, Neptune crossed Pluto’s path and is now
closer to the sun than Pluto and will remain that way for 228 years.
Discovery: When Uranus was discovered in 1781, John Couch Adams (of Britain) and Urbain Jean Joseph Leverrier (of France) noticed that it was pulled slightly out of orbit. Using reasoning, and mathematics, they independently figured out the exact mass and location of the planet influencing Uranus’ orbit. However, it was Johann Gottfried Galle who observed this planet in the Berlin Observatory, using Leverrier’s calculations, and was credited with Neptune’s discovery on September 23, 1846.
Fun Fact: In 1612, Galileo was the first person to observe Neptune. Unfortunately, he didn’t realize it was a planet and thought it was a star.
Gas Planet: Neptune is the smallest gas planet. Like all gas planets, it has no defined surfaces so volume and diameter measurements measure the outermost layer. It is Uranus’ twin planet and has the same internal structure as Uranus. Also like Uranus, it has a strong magnetic field, probably caused by ground water.
Gas Planets
Composition: It has a liquid rock core surrounded by ice, hydrogen, helium and methane. It also has deep oceans thought to contain water.
Rings: Neptune has four sets of faint rings that were thought to have been incomplete until the Voyager 2 arrived and proved otherwise on August 25, 1989. The rings are made of dust particles about the size of a car or a truck. The rings of Neptune are significantly smaller than the rings of Uranus, which have about a thousand times more matter. Neptune’s rings spread across 125,000 km, or 77,500 miles.
"Three Arcs of Neptune": These areas are anomalies located in Neptune’s outermost rings. In these areas, the rings are denser than the other parts of the rings. The higher density should have spread out over time until the rings became uniformly dense, but that did not happen.
Moons: Neptune has thirteen known moons, which are listed below.
Moon
|
Description (Origin of Names and Interesting Facts)
|
Date of Discovery
|
Discovery Location
|
Discoverer
|
Neptune I (Triton)
|
The sea-god son of Poseidon (Neptune) and Amphitrite.
|
October 10, 1846
|
Liverpool
|
W. Lassell
|
Neptune II (Nereid)
|
The fifty daughters of Nereus and Doris and attendants of Neptune.
|
May 1, 1949
|
Fort Davis
|
G.P. Kuiper
|
Neptune III (Naiad)
|
Greek water nymphs who were guardians of lakes, fountains, springs, and rivers.
|
August 1989
|
Voyager 2
|
Voyager Science Team
|
Neptune IV (Thalassa)
|
Greek sea goddess. Mother of Aphrodite in some legends, Telchines in others.
|
August 1989
|
Voyager 2
|
Voyager Science Team
|
Neptune V (Despina)
|
Daughter of Poseidon (Neptune) and Demeter.
|
July 1989
|
Voyager 2
|
Voyager Science Team
|
Neptune VI (Galatea)
|
One of the fifty Nereids.
|
July 1989
|
Voyager 2
|
Voyager Science Team
|
Neptune VII (Larissa)
|
A lover of Poseidon.
|
July 1989
|
Voyager 2
|
Voyager Science Team
|
Neptune VIII (Proteus)
|
Greek sea god, son of Oceanus and Tethys.
|
June 1989
|
Voyager 2
|
Voyager Science Team
|
Neptune IX (Halimede)
|
One of the Nereids, the fifty daughters of Nereus and Doris.
|
August 14, 2002
|
Cerro Tololo
|
M. Holman, J. Kavelaars, T. Grav, W. Fraser, and D. Milisavljevic
|
Neptune X (Psamathe)
|
One of the Nereids, lover of Aeacus, mother of Phocus.
|
August 29, 2003
|
Mauna Kea
|
S.S. Sheppard, D.C. Jewitt, and J. Kleyna
|
Neptune XI (Sao)
|
One of the Nereids, the fifty daughters of Nereus and Doris.
|
August 14, 2002
|
Cerro Tololo
|
T. Grav, M. Holman, J. Kavelaars, W. Fraser, and D. Milisavljevic
|
Neptune XII (Laomedeia)
|
One of the Nereids, the fifty daughters of Nereus and Doris.
|
August 13, 2002
|
Cerro Tololo
|
J. Kavelaars, M. Holman, T. Grav, W. Fraser, and D. Milisavljevic
|
Neptune XIII (Neso)
|
One of the Nereids, the fifty daughters of Nereus and Doris.
|
August 14, 2002
|
Cerro Tololo
|
M. Holman, J. Kavelaars, T. Grav, W. Fraser, and D. Milisavljevic
|
Additional Information: Triton- Discovered by William Lassell, who funded his research with money from his brewery business, on October 10, 1846. Triton is Neptune’s largest moon. It is the only large moon that orbits its planet in the opposite direction. Because of this feature, Neptune’s gravity slows down the moon’s orbit and drags it closer to the planet. Eventually, Neptune’s gravity might destroy the planet and the moon might form a ring around the planet. Triton is also the coldest measured object in our Solar System at -235 C, or -391 F. It has ice volcanoes that sprout out liquid nitrogen, methane, and dust, which will freeze immediately upon leaving the volcano and snow down upon the planet. Sometimes, the material reaches five miles high.
Nereid- Discovered by Gerard Kuiper, for whom the Kuiper Belt was named. Found in May 1, 1949, it is Neptune’s third largest moon. It has the most unique orbit of all the moons in that it is seven times as far from Neptune at one end of its orbit than the other.
Proteus- The second largest of Neptune’s moons, it was discovered after Nereid, the third largest moon because it was too dark and too close to Neptune to be visible to the telescopes of that time period.
Unique Features: Winds- Neptune’s fast rotation of 16.11 hours, which is almost eight hours less than Earth’s rotation, expedites its fierce winds and storm systems. For that reason, it has the strongest measured winds on any planet. Winds can travel up to 2000 km/hr, or 1200 mi/hr.
Trojan- Neptune may have been escorted in its orbit by thousands of these asteroid-like objects. Recently, six Trojans have been found to share roughly the same orbit as Neptune.
South Pole- The South Pole is a lot hotter than the rest of the planet. Recently, scientists have discovered that Neptune’s southern hemisphere is getting brighter.
Great Dark Spot- This is a storm system the size of Earth, composed of high cirrus clouds. The cirrus clouds are made of frozen methane, due to the fact that temperatures can reach as low as 55 K or -360 F, and constantly dissapate and reform. The Great Dark Spot is similar to Jupiter's Great Red Spot and moves in the direction opposite to Neptune’s rotation at supersonic speeds.
Great Dark Spot
Neptune Statistics
|
Discovered by
|
Johann Gotfried Galle
|
Date of discovery
|
September 23, 1846
|
Mass (kg)
|
1.024e+26
|
Mass (Earth = 1)
|
1.7135e+01
|
Equatorial radius (km)
|
24,746
|
Equatorial radius (Earth = 1)
|
3.8799e+00
|
Mean density (gm/cm^3)
|
1.64
|
Mean distance from the Sun (km)
|
4,504,300,000
|
Mean distance from the Sun (Earth = 1)
|
30.0611
|
Rotational period (hours)
|
16.11
|
Orbital period (years)
|
164.79
|
Mean orbital velocity (km/sec)
|
5.45
|
Orbital eccentricity
|
0.0097
|
Tilt of axis (degrees)
|
29.56
|
Orbital inclination (degrees)
|
1.774
|
Equatorial surface gravity (m/sec^2)
|
11.0
|
Equatorial escape velocity (km/sec)
|
23.50
|
Visual geometric albedo
|
0.41
|
Magnitude (Vo)
|
7.84
|
Mean cloud temperature
|
-193 to -153°C
|
Atmospheric pressure (bars)
|
1-3
|
Atmospheric composition
Hydrogen
Helium
Methane
|
85%
13%
2%
|
Experiments:
Because of the enormous distance between Earth and Neptune, many of the experiments that scientists would like to perform are currently impossible. In addition, even though astronomers can send probes to the planet to take pictures and uncover interesting or important information, the sheer distance from Earth means that the probe will take years to reach the planet, if they reach the planet at all. Despite the fact that there are pages upon pages of information about this planet, many things remain unknown. The following is a list of proposed experiments whose results can enlighten the scientific community, even if scientists do not yet have the power to carry them out.
Experiment 1:
Purpose: What if there exists a being completely different from the inhabitants of Earth, a being not solid, but gaseous? In this experiment a probe will be sent on a search for possible gaseous life forms by analyzing the air. It will relay the condition or quality of air on Neptune, if nothing else.
Procedure: Send a unique probe based on the Voyager 2 to Neptune. It will vacuum air or gas from three distinct areas on Neptune: Area 1 – An extreme with the strongest, fiercest conditions, including exceptionally low temperatures and the fiercest winds. Area 2 – The other extreme with the calmest conditions, moderate temperatures, and the least winds. Area 3 – The area between the extremes. This area has conditions between the two extreme areas. These three areas were chosen so that no condition will be left out, because no matter how unlikely, there is a possibility that there are life forms living in the extreme areas. After the samples are collected, the space probe will analyze them with its built in lab and search for any anomalies. Conclusions will be drawn based on the lab results.
Difficulties: Entering Neptune’s atmosphere and navigating through the planet without being destroyed by the intense winds.
Equipment: The following equipment will all be used for the other two experiments.
Voyager Based: Science Instrument Boom
Advanced Cameras and Spectrometer
Cosmic Ray Detector
Low Gain and High Gain Antennas
Star Trackers
Radioisotope Thermal Generators
Magnetometer Boom
Low Energy Charged Particle Detector
Other: Lab-Microscopy
Electrochemistry and Conductivity Analyzer
Thermal and Evolved-Gas Analyzer
Vacuum
Advances on a lightweight and flexible aluminum composite combined with layers of Kevlar
Experiment 2:
Purpose: The “Three Arcs of Neptune” are an anomaly in that they are denser than any other part of the rings, even though the density should be uniform throughout the rings. In this experiment, a probe will be sent to discover why they are such an anomaly. What causes them to be denser? In addition, if the density is due to the composition of the particles, this experiment will discover if the composition will be useful for future technological advances.
Procedure: Since the Voyager 2 has already proved that it can survive the trip to Neptune, a probe similar to this vehicle will be sent to the Neptune. This probe will situate itself near the arcs and observe them with a camera. It will try to discover if Neptune’s moons’ gravitational pulls are affecting these areas. If possible, it will retrieve a sample of the particles in these areas with a tractor beam. It will then analyze the particle in its built in lab and search for anomalies.
Equipment: All the equipment listed in Experiment 1 (See above).
Advances on a recently developed tractor beam that works on microscopic molecules.
Experiment 3:
Introduction: The water bear (Tardigrada) is an amazing animal. It has been proven to be able to survive the vacuum of space. In fact, despite ten days in space, the water bear was able to produce an embryo. It can survive a large quantity of radiation (5700 grays), temperatures close to absolute zero, and temperatures of up to 151 C or 303 F. It can live for 200 years. It can live decades without water and can go into suspended animation if it cannot find water. The longest recorded time the water bear was in suspended animation was over 100 years. This is the ideal animal to send to Neptune.
Purpose: Is Neptune habitable? Can this animal from Earth survive condition on Neptune?
Procedure: A vehicle similar to the Voyager will bring this animal to Neptune and go close to the planet’s atmosphere, or, if possible, enter the atmosphere. Then, it will release a water bear into the atmosphere along with its own personal satellite that will track the water bear. Since the water bear is supposedly the only living organism in immediate range, the tracker should have no trouble tracking the animal with motion sensor and heat sensor. It can also send out radio waves to detect the animal. The tracker will also have a camera to capture the water bear’s behavior.
Equipment: All the equipment listed in Experiment 1 (See above).
Water Bear
Tracker as described above: it will be made of material made from the advances on a lightweight and flexible aluminum composite combined with layers of Kevlar for strength and wind resistance.
Works Cited:
http://www.sciencedaily.com/news/space_time/neptune/
http://burro.astr.cwru.edu/stu/neptune.html
http://www.space.com/neptune/
http://www.space.com/scienceastronomy/solarsystem/neptune-ez.html
http://coolcosmos.ipac.caltech.edu//cosmic_kids/AskKids/neptune_discovery.shtml
http://www.space.com/scienceastronomy/070130_st_neptune_trojans.html
http://solarsystem.nasa.gov/planets/profile.cfm?Object=Neptune&Display=Moons
http://news.bbc.co.uk/2/hi/science/nature/1310771.stm
http://www.scienceray.com/Biology/Zoology/Extremely-Amazing-Animals-That-Sustain-Their-Survival-Under-Extreme-Conditions.253113
Pictures:
http://planetarynames.wr.usgs.gov/append7.html#NeptunianSystem
http://www.solarviews.com/eng/neptune.htm
http://www.edu.pe.ca/southernkings/Neptune.htm
http://www.astrophys-assist.com/educate/robot/images/gas-giants.jpg
http://www.arcadiastreet.com/cgvistas/neptune_006.htm
http://samadhi.jpl.nasa.gov/art/pix/neptune.jpg
Comments (3)
Peilin said
at 10:22 pm on Jan 11, 2009
the web page have more information now compare to before, the experiment is well lay out and interesting. information is well written.
Ivanna Subbotina said
at 5:15 pm on Jan 6, 2009
I thnk your web page was very organized and went straight to the point.
The experiments were very unique and it does look like you put some thought into them.
My favorite of the experiments was the first because it seemed to be the most realiztic of all.
Wenbin Zhao said
at 10:22 pm on Jan 4, 2009
Thorough information and pleasing to the eyes. However, maybe the experiment could be fancier with incorporations of tools that we haven't yet discovered, instead of everything based on our current technology. neverthless, it is a well done paper.
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