10 most difficult space riddlesSpace quiz
A star that pulsates radially, changing both diameter and temperature is called a ...
A Cepheid variable is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude. A strong direct relationship between a Cepheid variable's luminosity and pulsation period established Cepheids as important indicators of cosmic benchmarks for scaling galactic and extragalactic distances.
What is the name of the hypothetical last stage of the evolution of Sun-sized stars?
A black dwarf is a theoretical stellar remnant, specifically a white dwarf that has cooled sufficiently that it no longer emits significant heat or light
What is the second brightest star in the night time sky, after Sirius?
Canopus is the brightest star in the southern constellation of Carina, and the second brightest star in the night time sky, after Sirius. Its name is generally considered to originate from the mythological Canopus, who was a navigator for Menelaus, king of Sparta.
Which rover was the first to explore Mars?
Sojourner was the first Mars rover. It was much smaller than Curiosity, whose wheel is about the size of the whole Sojourner. It landed on July 4, 1997 as part of the Mars Pathfinder mission on Mars's Ares Vallis and remained in contact with Earth till September 27, 1997.
Which of the following cosmic structures is the largest?
Galaxy filaments are the largest known structures in the universe. They group galaxy superclusters, which in turn are formed by cluster composed of galaxies. Hercules–Corona Borealis Great Wall is considered the largest known structure of Universe. It is estimated to span 10 billions light years.
What type of nebula is the Horsehead Nebula?
Dark nebulae are clouds of dust which are simply blocking the light from whatever is behind. They are physically very similar to reflection nebulae; they look different only because of the geometry of the light source, the cloud and the Earth. Dark nebulae are also often seen in conjunction with reflection and emission nebulae. A typical diffuse nebula is a few hundred light-years across. (NGC 2264 shown; see also the Horsehead Nebula)
Which is the outermost moon of Neptune, also the most distant known moon of any planet?
Neso is the outermost known natural satellite of Neptune. It is an irregular moon discovered by Matthew J. Holman, Brett J. Gladman, et al. on August 14, 2002, though it went unnoticed until 2003. Neso orbits Neptune at a distance of more than 48 Gm (million km), making it (as of 2015) the most distant known moon of any planet.
What is the largest discovered star? (by radius)
VY Canis Majoris
UY Scuti is a bright red supergiant and pulsating variable star in the constellation Scutum. It is currently the largest known star by radius and is also one of the most luminous of its kind. It has an estimated radius of 1,708 solar radii (1.188×109 kilometres; 7.94 astronomical units); thus a volume nearly 5 billion times that of the Sun. It is approximately 2.9 kiloparsecs (9,500 light-years) from Earth. If placed at the center of the Solar System, its photosphere would at least engulf the orbit of Jupiter.
The idea that the nascent universe passes through the phase of exponential expansion, which was driven by the positive density of vacuum energy, is called;
Grand unification theory
Theory of Supersymmetry
All answers are correct.
Alan Guth formally proposed the idea of cosmic inflation in 1981, the idea that the nascent universe passed through a phase of exponential expansion that was driven by a positive vacuum energy density (negative vacuum pressure).