Search NASA⌕ Search

SEARCH · Search NASA

Results for “planet search”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Oscillations of the Atmospheric Dynamic State in Simulations of LP 890-9 c

Through the identification and characterization of exoplanet atmospheres, we will soon begin to truly understand the evolution and habitability of extrasolar terrestrial planets. Due to their long main-sequence lifetimes and relatively low luminosities, planets orbiting M dwarf stars are the focus of these searches. Delrez et al. (2022) identified a planet, LP 890-9 c orbiting a faint M6 star. Both LP 890-9 c and the inner planet LP 890-9 b are likely rocky, with radii of ≈ 1.3R Ꚛ . Planet b is well inward of the classical habitable zone (HZ), although LP 890-9 c has an instellation of 0.906 S Ꚛ –placing it near the inner edge of the HZ. Our limited understanding of the co-evolution of rocky planets and M dwarf host stars make LP 890-9 c an ideal subject to test the possible climatic outcomes for the inner edge of the HZ such stars.

LP 890-9 c↗
NASA NTRS2019

Expected Occurrence Rates and Types of Planets Possible in the Alpha Centauri AB System

Alpha Centauri AB system contains the closest Sun-like stars to the Sun, by a large margin (factor of 2.4). Thus, they are important targets for the search of Earth-like planets. A critical question is whether such planets can exist in the system, and what their expected occurrence rate is. This paper surveys the current knowledge of occurrence rates, limits from nondetections, constraints from observations, and dynamical stability simulations, in order to answer this question.

Belikov, Ruslan↗
NASA NTRS2004

Planning and Execution: The Spirit of Opportunity for Robust Autonomous Systems

One of the most exciting endeavors pursued by human kind is the search for life in the Solar System and the Universe at large. NASA is leading this effort by designing, deploying and operating robotic systems that will reach planets, planet moons, asteroids and comets searching for water, organic building blocks and signs of past or present microbial life. None of these missions will be achievable without substantial advances in.the design, implementation and validation of autonomous control agents. These agents must be capable of robustly controlling a robotic explorer in a hostile environment with very limited or no communication with Earth. The talk focuses on work pursued at the NASA Ames Research center ranging from basic research on algorithm to deployed mission support systems. We will start by discussing how planning and scheduling technology derived from the Remote Agent experiment is being used daily in the operations of the Spirit and Opportunity rovers. Planning and scheduling is also used as the fundamental paradigm at the core of our research in real-time autonomous agents. In particular, we will describe our efforts in the Intelligent Distributed Execution Architecture (IDEA), a multi-agent real-time architecture that exploits artificial intelligence planning as the core reasoning engine of an autonomous agent. We will also describe how the issue of plan robustness at execution can be addressed by novel constraint propagation algorithms capable of giving the tightest exact bounds on resource consumption or all possible executions of a flexible plan.

Muscettola, Nicola↗
NASA NTRS1990

Pioneers 10 and 11 deep space missions

Pioneers 10 and 11 were launched from Earth, 2 March 1972, and 5 April 1973, respectively. The Pioneers were the first spacecraft to explore the asteroid belt and the first to encounter the giant planets, Jupiter and Saturn. The Pioneer 10 spacecraft is now the most distant man-made object in our solar system and is farther from the Sun than all nine planets. It is 47 AU from the Sun and is moving in a direction opposite to that of the Sun's motion through the galaxy. Pioneer 11 is 28 AU from the Sun and is traveling in the direction opposite of Pioneer 10, in the same direction as the Sun moves in the galaxy. These two Pioneer spacecraft provided the first large-scale, in-situ measurements of the gas and dust surrounding a star, the Sun. Since launch, the Pioneers have measured large-scale properties of the heliosphere during more than one complete 11-year solar sunspot cycle, and have measured the properties of the expanding solar atmosphere, the transport of cosmic rays into the heliosphere, and the high-energy trapped radiation belts and magnetic fields associated with the planets Jupiter and Saturn. Accurate Doppler tracking of these spin-stabilized spacecraft was used to search for differential gravitational forces from a possible trans-Neptunian planet and to search for gravitational radiation. Future objectives of the Pioneer 10 and 11 missions are to continue measuring the large-scale properties of the heliosphere and to search for its boundary with interstellar space.

Dyal, Palmer↗
NASA NTRS1990

Pioneers 10 and 11 deep space missions

Pioneers 10 and 11 were launched from earth, 2 March 1972, and 5 April 1973, respectively. The Pioneers were the first spacecraft to explore the asteroid belt and the first to encounter the giant planets, Jupiter and Saturn. The Pioneer 10 spacecraft is now the most distant man-made object in our solar system and is farther from the sun than all nine planets. It is 47 AU from the sun and is moving in a direction opposite to that of the sun's motion through the galaxy. Pioneer 11 is 28 AU from the sun and is traveling in the direction opposite of Pioneer 10, in the same direction as the sun moves in the galaxy. These two Pioneer spacecraft provided the first large-scale, in-situ measurements of the gas and dust surrounding a star, the sun. Since launch, the Pioneers have measured large-scale properties of the heliosphere during more than one complete 11-year solar sunspot cycle, and have measured the properties of the expanding solar atmosphere, the transport of cosmic rays into the heliosphere, and the high-energy trapped radiation belts and magnetic fields associated with the planets Jupiter and Saturn. Accurate Doppler tracking of these spin-stabilized spacecraft was used to search for differential gravitational forces from a possible trans-Neptunian planet and to search for gravitational radiation. Future objectives of the Pioneer 10 and 11 missions are to continue measuring the large-scale properties of the heliosphere and to search for its boundary with interstellar space.

Dyal, P.↗
NASA NTRS2001

Searching for life in the universe: lessons from the earth

Space programs will soon allow us to search for life in situ on Mars and to return samples for analysis. A major focal point is to search for evidence of present or past life in these samples, evidence that, if found, would have far-reaching consequences for both science and religion. A search strategy will consider the entire gamut of life on our own planet, using that information to frame a search that would recognize life even if it were fundamentally different from that we know on Earth. We discuss here how the lessons learned from the study of life on Earth can be used to allow us to develop a general strategy for the search for life in the Universe.

Extraterrestrial Environment↗
NASA NTRS2019

Time Series Analysis in the Search for Other Worlds Through Transit Photometry

The Kepler Mission launched in June 2009 to commence NASA's first mission to search for potentially habitable, Earth-size planets orbiting Sun-like stars. Kepler discovered explanets via the transit method: searching for minute (100 ppm) drops in brightness lasting 1 - 13 hours corresponding to occasions where the planet crosses the face of its host star from Kepler's point of view. The exquisite precision required to carry out the Kepler mission (20 ppm in 6.5 hours) pushed astronomical time series analysis to the limits, and motivated the development of novel algorithmic approaches. Transit signatures of rocky planets are often dwarfed by the intrinsic stellar variability, which is not white noise, and often is non-stationary, and by instrumental systematic effects, which can include transients and electronic artifacts. Surmounting this challenging regime of weak, temporally compact, periodic signals in observation noise with strong systematics and other sources of variability motivated the development of 1) an overcomplete, non-decimated, wavelet-based matched filter to jointly estimate the properties of the non-stationary, non-white observation noise process, and 2) a multi-scale, maximum a posteriori (msMAP) approach to identifying and removing instrumental systematic effects. After over nine years of observations, the Kepler spacecraft finally ran out of fuel in November 2018, ending its data collection activities. Over 2300 planets were discovered by Kepler in its primary mission, and over 355 have been discovered by K2, the repurposed mission that followed Kepler's primary mission after the loss of a second reaction wheel in May 2013. We have ported the Kepler science pipeline for the Transiting Exoplanet Survey Satellite (TESS) Mission, which began science observations in July 2019, and report initial results and performance of the modified science pipeline.The Kepler and TESS Missions are supported by NASA's Science Mission Directorate.

transit surveys↗
NASA NTRS2000

Detection of Extrasolar Planets by Transit Photometry

A knowledge of other planetary systems that includes information on the number, size, mass, and spacing of the planets around a variety of star types is needed to deepen our understanding of planetary system formation and processes that give rise to their final configurations. Recent discoveries show that many planetary systems are quite different from the solar system in that they often possess giant planets in short period orbits. The inferred evolution of these planets and their orbital characteristics imply the absence of Earth-like planets near the habitable zone. Information on the properties of the giant-inner planets is now being obtained by both the Doppler velocity and the transit photometry techniques. The combination of the two techniques provides the mass, size, and density of the planets. For the planet orbiting star HD209458, transit photometry provided the first independent confirmation and measurement of the diameter of an extrasolar planet. The observations indicate a planet 1.27 the diameter of Jupiter with 0.63 of its mass (Charbonneau et al. 1999). The results are in excellent agreement with the theory of planetary atmospheres for a planet of the indicated mass and distance from a solar-like star. The observation of the November 23, 1999 transit of that planet made by the Ames Vulcan photometer at Lick Observatory is presented. In the future, the combination of the two techniques will greatly increase the number of discoveries and the richness of the science yield. Small rocky planets at orbital distances from 0.9 to 1.2 AU are more likely to harbor life than the gas giant planets that are now being discovered. However, new technology is needed to find smaller, Earth-like planets, which are about three hundred times less massive than Jupiter-like planets. The Kepler project is a space craft mission designed to discover hundreds of Earth-size planets in and near the habitable zone around a wide variety of stars. To demonstrate that the technology exists to find such small planets, our group has conducted an end-to-end system test. The results of the laboratory tests are presented and show that we are ready to start the search for Earth-size planets.

Borucki, William↗
NASA NTRS1998

Radial Velocity Detection of Extra-Solar Planetary Systems

The McDonald Observatory Planetary Search (MOPS) was designed to search for Jovian-mass planets in orbit around solar-type stars by making high-precision measurements of the Radial Velocity (RV) of a star, to attempt to detect the reflex orbital motion of the star around the star-planet barycenter. In our solar system, the velocity of the Sun around the Sun-Jupiter barycenter averages 12.3 m/ s. The MOPS survey started operation in September 1987, and searches 36 bright, nearby, solar-type dwarfs to 10 m/s precision. The survey was started using telluric O2 absorption lines as the velocity reference metric. Observations use the McDonald Observatory 2.7-m Harlan Smith Telescope coude spectrograph with the six-foot camera. This spectrograph configuration isolates a single order of the echelle grating on a Texas Instruments 800 x 800 CCD. The telluric line method gave us a routine radial velocity precision of about 15 m/s for stars down to about 5-th magnitude. However, the data obtained with this technique suffered from some source of long-term systematic errors, which was probably the intrinsic velocity variability of the terrestrial atmosphere, i.e. winds. In order to eliminate this systematic error and to improve our overall measurement precision, we installed a stabilized I2 gas absorption cell as the velocity metric for the MOPS in October 1990. In use at the telescope, the cell is placed directly in front of the spectrograph entrance slit, with starlight passing through the cell. The use of this sealed stabilized I2 cell removes potential problems with possible long-term drifts in the velocity metric. The survey now includes a sample of 36 nearby F, G, and K type stars of luminosity class V or IV-V.

Cochran, William D.↗
NASA NTRS2004

Design and Performance of the Terrestrial Planet Finder Coronagraph

Terrestrial Planet Finder Coronagraph, one of two potential architectures, is described. The telescope is designed to make a visible wavelength survey of the habitable zones of at least thirty stars in search of earth-like planets. The preliminary system requirements, optical parameters, mechanical and thermal design, operations scenario and predicted performance is presented. The 6-meter aperture telescope has a monolithic primary mirror, which along with the secondary tower, are being designed to meet the stringent optical tolerances of the planet-finding mission. Performance predictions include dynamic and thermal finite element analysis of the telescope optics and structure, which are used to make predictions of the optical performance of the system.

designs↗
NASA NTRS2004

NASA's Terrestrial Planet Finder Missions

NASA has decided to move forward with two complementary Terrestrial Planet Finder (TPF) missions, a visible coronagraph and an infrared formation flying interferometer. These missions are major missions in the NASA Office of Space Science Origins Theme. The primary science objectives of the TPF missions are to search for, detect, and characterize planets and planetary systems beyond our own Solar System, including specifically Earth-like planets.

Terrestrial Planet Finder (TPF)↗
NASA NTRS2012

The Search for Life on Mars - Current Knowledge, Earth Analogues, and Principal Issues

For centuries, the planet Mars has been imagined as a possible abode for life. Serious searches for life's signatures began in the 19th century via ground-based visual astronomy that stimulated a vibrant fantasy literature but little lasting scientific knowledge. Modern scientific inquiry has emphasized the search for chemical signatures of life in the soil and rocks at the planet's surface, and via biomarker gases in the atmosphere. Today, investigations are based on high-resolution spectroscopy at Earth's largest telescopes along with planet orbiting and landed space missions. Methane has assumed central importance in these searches. Living systems produce more than 900/0 of Earth's atmospheric methane; the balance is of geochemical origin. Abundant methane is not expected in an oxidizing atmosphere such as Mars', and its presence would imply recent release - whether biological or geochemical. F or that reason, the quest for methane on Mars has been a continuing thread in the fabric of searches conducted since 1969. I will review aspects of the discovery and distribution of methane on Mars, and will mention ongoing extended searches for clues to its origin and destruction. On Earth, hydrogen (generated via serpentinization or radiolysis of water) provides an important 'fuel' for carbonate-reducing and sulphate-reducing biota (CH4 and H2S producers, respectively). Several such communities are known to reside at depth in continental domains (e.g., Lidy Hot Springs, Idaho; Witwatersrand Basin, S. Africa). If similar conditions exist in favourable locations on Mars, organisms similar to these could likely prosper there. Geologic (abiotic) production will also be mentioned, especially abiotic methane production associated with low-temperature serpentinization (e.g., terrestrial ophiolites). It is vitally important to pursue evidence for geochemical and biological production with equal vigour and intellectual weight lest unwanted and unintended bias contaminate the results. Finally, I will touch upon unresolved questions and issues posed by the methane detections.

Mumma, Michael J.↗
NASA NTRS2007

The SIM PlanetQuest Science Program

SIM PlanetQuest (hereafter, just SIM) is a NASA mission to measure the angular positions of stars with unprecedented accuracy. We outline the main astrophysical science programs planned for SIM, and related opportunities for community participation. We focus especially on SIM's ability to detect exoplanets as small as the Earth around nearby stars. The planned synergy between SIM and other planet-finding missions including Kepler and GAIA, and planet-characterizing missions including the James Webb Space Telescope (JWST), Terrestrial Planet Finder--Coronagraph (TPF-C), and Terrestrial Planet Finder--Interferometer (TPF-I), is a key element in NASA's Navigator Program to find Earth-like planets, determine their habitability, and search for signs of life in the universe. SIM's technology development is now complete and the project is proceeding towards a launch in the next decade.

SIM PlanetQuest (SIM)↗
NASA NTRS2020

TOI 564 b and TOI 905 b: Grazing and Fully Transiting Hot Jupiters Discovered by TESS

We report the discovery and confirmation of two new hot Jupiters discovered by the Transiting Exoplanet Survey Satellite(TESS): TOI 564 b and TOI 905 b. The transits of these two planets were initially observed by TESS with orbital periods of 1.651 and 3.739 days, respectively. We conducted follow-up observations of each system from the ground, including photometry in multiple filters, speckle interferometry, and radial velocity measurements. For TOI 564 b, our global fitting revealed a classical hot Jupiter with a mass of-+1.4630.0960.10MJand a radius of-+1.020.290.71RJ. Also a classical hot Jupiter, TOI 905 b has a mass of-+0.6670.0410.042MJand radius of-+1.1710.0510.053RJ. Both planets orbit Sun-like, moderately bright, mid-G dwarf stars with V11. While TOI 905 b fully transits its star, we found that TOI 564 b has a very high transit impact parameter of-+0.9940.0490.083, making it one of only∼20 known systems to exhibit a grazing transit and one of the brightest host stars among them. Therefore, TOI 564 b is one of the most attractive systems to search for additional nontransiting, smaller planets by exploiting the sensitivity of grazing transits to small changes in inclination and transit duration over a timescale of several years.

Exoplanet astronomy↗
NASA NTRS1986

Review of methodology and technology available for the detection of extrasolar planetary systems

Anyone undertaking an interstellar voyage might wish to be assured of the existence of a safe planetary harbor at the other end! Aside from the obvious interest of the participants in this Symposium, astronomers and astrophysicists are also eager to detect and study other planetary systems in order to better understand the formation of our own Solar System. Scientists involved in the search for extraterrestrial intelligence argue that planets suitable for the evolution of life may abound elsewhere within our own Milky Way Galaxy. On theoretical grounds, they are probably correct, but they lack any observational support. For in spite of decades of claimed astrometric detections of planetary companions and the recent exciting and tantalizing observations from the IRAS satellite and the IR speckle observations of Van Biesbroeck 8 and other cool stars, there is no unambiguous proof for the existence of another planetary system beyond our own. In this paper we review the various methods for detecting extrasolar planets and briefly describe the Earth and space based technology currently available and discuss the near-term plans to implement these different search techniques. In each case an attempt is made to identify the limiting source of systematic error inherent to the methodology and to assess the potential for technological improvements.

Non-NASA Center↗
NASA NTRS2009

Kepler: NASA's First Mission Capable of Finding Earth-Size Planets

Kepler, a NASA Discovery mission, is a spaceborne telescope designed to search a nearby region of our galaxy for Earth-size planets orbiting in the habitable zone of stars like our sun. The habitable zone is that region around a start where the temperature permits water to be liquid on the surface of a planet. Liquid water is considered essential forth existence of life. Mission Phases: Six mission phases have been defined to describe the different periods of activity during Kepler's mission. These are: launch; commissioning; early science operations, science operations: and decommissioning

Borucki, William J.↗
NASA NTRS2004

The Search for Young Planetary Systems And the Evolution of Young Stars

The Space Interferometer Mission (SIM) will provide a census of planetary systems by con- ducting a broad survey of 2,000 stars that will be sensitive to the presence of planets with masses as small as approx. 15 Earth masses (1 Uranus mass) and a deep survey of approx. 250 of the nearest, stars with a mass limit of approx.3 Earth masses. The broad survey will include stars spanning a wide range of ages, spectral types, metallicity, and other important parameters. Within this larger context, the Young Stars and Planets Key Project will study approx. 200 stars with ages from 1 Myr to 100 Myr to understand the formation and dynamical evolution of gas giant planets. The SIM Young Stars and Planets Project will investigate both the frequency of giant planet formation and the early dynamical history of planetary systems. We will gain insight into how common the basic architecture of our solar system is compared with recently discovered systems with close-in giant planets by examining 200 of the nearest (less than 150 pc) and youngest (1-100 Myr) solar-type stars for planets. The sensitivity of the survey for stars located 140 pc away is shown in the planet mass-separation plane. We expect to find anywhere from 10 (assuming that only the presently known fraction of stars. 5-7%, has planets) to 200 (all young stars have planets) planetary systems. W-e have set our sensitivity threshold to ensure the detection of Jupiter-mass planets in the critical orbital range of 1 to 5 AU. These observations, when combined with the results of planetary searches of mature stars, will allow us to test theories of planetary formation and early solar system evolution. By searching for planets around pre-main sequence stars carefully selected to span an age range from 1 to 100 Myr, we will learn a t what epoch and with what frequency giant planets are found at the water-ice snowline where they are expected to form. This will provide insight into the physical mechanisms by which planets form and migrate from their place of birth, and about their survival rate. With these data in hand, we will provide data, for the first time, on such important questions as: What processes affect the formation and dynamical evolution of planets? When and where do planets form? What is initial mass distribution of planetary systems around young stars? How might planets be destroyed? What is the origin of the eccentricity of planetary orbits? What is the origin of the apparent dearth of companion objects between planets and brown dwarfs seen in mature stars? The observational strategy is a compromise between the desire to extend the planetary mass function as low as possible and the essential need to build up sufficient statistics on planetary occurrence. About half of the sample will be used to address the "where" and "when" of planet formation. We will study classical T Tauri stars (cTTs) which have massive accretion disks and post- accretion, weak-lined T Tauri stars (wTTs). Preliminary estimates suggest the sample will consist of approx. 30% cTTs and approx. 70% wTTs, driven in part by the difficulty of making accurate astrometric measurements toward objects with strong variability or prominent disks.

Beichman, Charles A.↗
NASA NTRS2006

Linking Yellowstone Research to Mars Exploration

Yellowstone's hydrothermal features and their associated communities of thermophiles are studied by scientists who are searching for evidence of life on other planets. The connection is extreme environments. If life originated in the extreme conditions thought to have been widespread on ancient Earth, it may well have developed on other planets and it might still exist today. The chemosynthetic microbes that thrive in some of Yellowstone s hot springs do so by metabolizing inorganic chemicals, a source of energy that does not require sunlight. Such chemical energy sources provide the most likely habitable niches for life on Mars or on the moons of Jupiter-Ganymede, Europa, and Callisto-where uninhabitable surface conditions preclude photosynthesis. Chemical energy sources, along with extensive groundwater systems (such as on Mars) or oceans beneath icy crusts (such as Jupiter's moons) could provide habitats for life. The study of stromatolites on Earth may also be applied to the search for life on other planets. If stromatolites are eventually found in the rocks of Mars or on other planets, we will have proven that life once existed elsewhere in the universe. Yellowstone National Park will continue to be an important site for studies at the physical and chemical limits of survival. These studies will give scientists a better understanding of the conditions that give rise to and support life, and they will learn how to recognize signatures of life in ancient rocks and on distant planets.

DesMarais, David J.↗