A5001352997- Astro and Planetary Science
- Planetary Science and Exploration
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Isotope Analysis in Ecology
- Space Satellite Systems and Control
- Geomagnetism and Paleomagnetism Studies
- Astronomical Observations and Instrumentation
- Space Exploration and Technology
- Scientific Research and Discoveries
- Astrophysics and Star Formation Studies
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Geology and Paleoclimatology Research
- Space Science and Extraterrestrial Life
- Laser-induced spectroscopy and plasma
- Astronomical and nuclear sciences
- Geological and Geochemical Analysis
- Spacecraft and Cryogenic Technologies
- Nuclear physics research studies
- Spacecraft Design and Technology
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Spacecraft Dynamics and Control
University of Helsinki
2016-2025
Luleå University of Technology
2018-2025
Helsinki Institute of Physics
2014-2023
Max Planck Society
2018
Jet Propulsion Laboratory
2018
University of Bern
2017
Finnish Geospatial Research Institute
2014-2016
Monterey Institute for Research in Astronomy
2010-2012
University of Hawaii System
2008-2012
The asteroid impact near the Russian city of Chelyabinsk on 15 February 2013 was largest airburst Earth since 1908 Tunguska event, causing a natural disaster in an area with population exceeding one million. Because it occurred era modern consumer electronics, field sensors, and laboratory techniques, unprecedented measurements were made event meteoroid that caused it. Here, we document account what happened, as understood now, using comprehensive data obtained from astronomy, planetary...
The debiased absolute-magnitude and orbit distributions as well source regions for near-Earth objects (NEOs) provide a fundamental frame of reference studies individual NEOs more complex population-level questions. We present new four-dimensional model the NEO population that describes steady-state semimajor axis, eccentricity, inclination, absolute magnitude $H$ in range $17<H<25$. modeling approach improves upon methodology originally developed by Bottke et al. (2000; Science 288,...
Some active asteroids have been proposed to be formed as a result of impact events1. Because are generally discovered by chance only after their tails fully formed, the process how ejecta evolve into tail has, our knowledge, not directly observed. The Double Asteroid Redirection Test (DART) mission NASA2, in addition having successfully changed orbital period Dimorphos3, demonstrated activation an asteroid resulting from under precisely known conditions. Here we report observations DART with...
We describe the Pan-STARRS Moving Object Processing System (MOPS), a modern software package that produces automatic asteroid discoveries and identifications from catalogs of transient detections next-generation astronomical survey telescopes. MOPS achieves > 99.5% efficiency in producing orbits synthetic but realistic population asteroids whose measurements were simulated for Pan-STARRS4-class telescope. Additionally, using non-physical grid population, we demonstrate can detect populations...
Abstract The Outer Solar System Origins Survey (OSSOS), a wide-field imaging program in 2013–2017 with the Canada–France–Hawaii Telescope, surveyed 155 deg 2 of sky to depths m r = 24.1–25.2. We present 838 outer solar system discoveries that are entirely free ephemeris bias. This increases inventory trans-Neptunian objects (TNOs) accurately known orbits by nearly 50%. Each minor planet has 20–60 Gaia /Pan-STARRS-calibrated astrometric measurements made over 2–5 oppositions, which allows...
Aims. We locate escape routes from the main asteroid belt, particularly into near-Earth-object (NEO) region, and estimate relative fluxes for different as a function of object size under influence Yarkovsky semimajor-axis drift.
The Gaia spacecraft of the European Space Agency (ESA) has been securing observations solar system objects (SSOs) since beginning its operations. Data Release 2 (DR2) contains a selected sample 14,099 SSOs. These asteroids have already identified and numbered by Minor Planet Center. Positions are provided for each observation at CCD level. As additional information, apparent brightness SSOs in unfiltered G band is also observations. We explain processing SSO data, describe criteria we used...
Abstract Near-Earth Objects (NEOs) are a transient population of small bodies with orbits near or in the terrestrial planet region. They represent mid-stage dynamical cycle asteroids and comets, which starts their removal from respective source regions—the main belt trans-Neptunian scattered disk—and ends as impact planets, disintegrate Sun, ejected solar system. Here we develop new orbital model NEOs by numerically integrating asteroid main-belt sources calibrating results on observations...
The Vera C. Rubin Observatory is expected to start the Legacy Survey of Space and Time (LSST) in early mid-2025. This multi-band wide-field synoptic survey will transform our view solar system, with discovery monitoring over 5 million small bodies.The final strategy chosen for LSST has direct implications on discoverability characterization system minor planets passing interstellar objects. Creating an inventory one four main science drivers. observing cadence a complex optimization problem...
Abstract Numerical modeling has long suggested that gravitationally bound (or so-called rubble-pile) near-Earth asteroids (NEAs) can be destroyed by tidal forces during close and slow encounters with terrestrial planets. However, disruptions of NEAs have never been directly observed nor they attributed to any families NEAs. Here we show population-level evidence for the disruption Earth Venus. Debiased model distributions NEA orbits absolute magnitudes based on observations Catalina Sky...
Over the past decade there has been a large increase in number of automated camera networks that monitor sky for fireballs. One goals these is to provide necessary information linking meteorites their pre-impact, heliocentric orbits and ultimately source regions solar system. We re-compute 25 meteorite falls published date from original data sources. Using orbits, we constrain most likely escape routes main asteroid belt cometary region by utilizing state-of-the-art orbit model...
We report the discovery, tracking and detection circumstances for 85 trans-Neptunian objects (TNOs) from first 42 deg$^{2}$ of Outer Solar System Origins Survey (OSSOS). This ongoing $r$-band survey uses 0.9 field-of-view MegaPrime camera on 3.6 m Canada-France-Hawaii Telescope. Our orbital elements these TNOs are precise to a fractional semi-major axis uncertainty $<0.1\%$. achieve this precision in just two oppositions, as compared normal 3-5 via dense observing cadence innovative...
Abstract We report a statistically significant detection of nongravitational acceleration on the subkilometer near-Earth asteroid (523599) 2003 RM. Due to its orbit, RM experiences favorable observing apparitions every 5 yr. Thus, since discovery, has been extensively tracked with ground-based optical facilities in 2003, 2008, 2013, and 2018. find that observed plane-of-sky positions cannot be explained purely gravity-driven trajectory. Including transverse allows us match all observational...
Abstract We have monitored the Didymos–Dimorphos binary system in imaging polarimetric mode before and after impact from Double Asteroid Redirection Test mission. A previous spectropolarimetric study showed that caused a dramatic drop polarization. Our longer-term monitoring shows polarization of post-impact remains lower than pre-impact even months impact, suggesting some fresh ejecta material at time our observations, either orbit or settled on surface. The slope curve is shallower system,...
The near-Earth objects (NEOs) (3200) Phaethon and (155140) 2005 UD are thought to share a common origin, with the former exhibiting dust activity at perihelion that is directly supply Geminid meteor stream. Both of these currently have very small distances, which results in them having temperatures or exceeding 1000 K. current from relevant destruction NEOs close Sun, most likely has produced streams linked asteroids past. We model past thermal characteristics using combination...
Abstract We report 491 new near-infrared spectroscopic measurements of 420 near-Earth objects (NEOs) collected on the NASA InfraRed Telescope Facility as part MIT-Hawaii NEO Spectroscopic Survey. These were combined with previously published data from Binzel et al. and bias-corrected to derive intrinsic compositional distribution overall population, well subpopulations coming various escape routes (ERs) in asteroid belt beyond. The resulting distributions reflect gradient belt, decreasing...