Solar System[a] is the gravitationallybound system of the Sun and the objects that orbit it, either directly or indirectly,[b] including the eight planets and five dwarf planets as defined by the International Astronomical Union (IAU). Of the objects that orbit the Sun directly, the largest eight are the planets,[c]with the remainder being smaller objects, such as dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly—the moons—two are larger than the smallest planet, Mercury.[d]
Solar System
The Sun and planets of the Solar System (distances not to scale)
Age4.568 billion yearsLocation
Local Interstellar Cloud, Local Bubble,
Orion–Cygnus Arm, Milky Way
System mass1.0014 Solar massesNearest star
Proxima Centauri (4.25ly)
Alpha Centauri (4.37 ly)
Nearest knownplanetary systemProxima Centaurisystem (4.25 ly)Semi-major axis of outer known planet (Neptune)30.10 AU (4.503 billion km)Distance to Kuiper cliff50 AU
Populations
Stars1 (Sun)Known planets
8 (Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune)
Known dwarf planets
Possibly several hundred;[1] five currently recognized by the IAU
(Ceres
Pluto
Haumea
Makemake
Eris)
Known natural satellites
525
(185 planetary[2]
347 minor planetary[3])
Known minor planets778,897 (as of 2018-06-21)[4]Known comets4,017 (as of 2018-06-21)[4]Identified rounded satellites19Invariable-to-galactic plane inclination60.19° (ecliptic)Distance to Galactic Center27,000 ± 1,000 lyOrbital speed220 km/sOrbital period225–250 MyrSpectral typeG2VFrost line≈5 AU[5]Distance to heliopause≈120 AUHill sphere radius≈1–3 ly
The Solar System formed 4.6 billion years agofrom the gravitational collapse of a giant interstellar molecular cloud. The vast majority of the system's mass is in the Sun, with the majority of the remaining mass contained in Jupiter. The four smaller inner planets, Mercury, Venus, Earth and Mars, are terrestrial planets, being primarily composed of rock and metal. The four outer planets are giant planets, being substantially more massive than the terrestrials. The two largest, Jupiterand Saturn, are gas giants, being composed mainly of hydrogen and helium; the two outermost planets, Uranus and Neptune, are ice giants, being composed mostly of substances with relatively high melting points compared with hydrogen and helium, called volatiles, such as water, ammonia and methane. All eight planets have almost circular orbits that lie within a nearly flat disc called the ecliptic.
Answer:External respiration occurs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar air. Internal respiration occurs in the metabolizing tissues, where oxygen diffuses out of the blood and carbon dioxide diffuses out of the cells.
The correct answer is: a. directs somatic motor axons to four of the six extrinsic eye muscles and also transmits parasympathetic visceromotor impulses to pupillary constrictor muscle of the eye.
Explanation:
<u>The </u><u>oculomotor nerve </u><u>(III) is the third cranial nerve.</u> It provides motor innervation to four of the six extrinsic muscles of the eye and has also a parasympathetic component in charge of contracting the pupil when the environment is rich in light.
The cranial nerve that innervates the lateral rectus muscles of the eye is the abducens nerve (VI).
The cranial nerve that provides motor innervation to the superior oblique muscle of the eye is the trochlear nerve (IV).
Your genotype<span> is your complete heritable genetic identity; it is your unique genome that would be revealed by personal genome sequencing. However, the word ...</span>
The traits an organism displays are ultimately determined by the genes it inherited from its parents, in other words by its genotype. Animals have two copies of all their chromosomes, one from each parent.
Kinetic energy is a property of a moving object or particle and depends not only on its motion but also on its mass. The temperature of gases is proportional to the average translational kinetic energy of atoms and molecules. The motion of individual molecules in a gas is random in magnitude and direction.
